Bio lec1

Unit 1

Introduction

Objectives

4. Name the common elements and compounds required by living organisms.

3. Identify the important organelles of the cell.

1. Enumerate the attributes of living matter.

2. Distinguish between prokaryotes and eukaryotes.

Biochemistry

biomolecules

is the chemistry of biomolecules and their chemical reactions in living matter at the molecular and cellular level.

molecules involved in the survival of the living organism.

chemical reactions changes within the organism’s body usually referred to as biochemical reactions or metabolism.

What is a Biochemistry?

Biochemistry seeks to describe the structure, organization, and functions of living matter in molecular terms.

Level of Organization

1. Subatomic Paticles- an electron, proton, or neutron; three

major particles of which atoms are composed.

2. Atom- smallest unit of an element that still

remains the properties of that element.

3. Molecule- a unit of two or more atoms of the same

or different elements bonded together.

4. Organelle- any various membraneous sacs or other

compartments inside the cell that separate different metabolic reactions within the cellular space and in time. ribosome

5. Cell- smallest living unit; may live independently or may be part of a

multicellular organism.

red blood cell

6. Tissue- a group of similar cells and intercellular substances

functioning together in a specialized activity.

jellyfish

7. Organ- one or more types of of tissues interacting as a structural,

functioning unit.

brain

8. Organ system- two or more organs whose separate functions are integrated int the performance of a

special task.

•The heart is part of the circulatory system, which carries oxygen and other materials throughout the body. Besides the heart, blood vessels are organs that work in your circulatory system.

heart

9. Multicellular organism- individual composed of specialized,

interdependent cells arrayed in tissues, organs, and other organ system.

Biochemistry asks how the remarkable properties of living organisms arise from the thousands of different lifeless biomolecules.

It can be divided into three principal areas:1. Structural and Functional Biochemistry: Chemical

structures and 3D arrangements of molecules.

2. Informational Biochemistry: Language for storing biological data and for transmitting that data in cells and organisms.

3. Bioenergetics: The flow of energy in living organisms and how it is transferred from one process to another.

When these molecules are isolated and examined individually, they conform to all the physical and chemical laws that describe the behavior of inanimate matter - as do all the processes occurring in living organisms.

The study of biochemistry shows how the collections of inanimate molecules that constitute living organisms interact to maintain and perpetuate life animated solely by the physical and chemical laws that govern the nonliving universe.

Physical and Chemical sciences alone may not completely explain the nature of life, but they at least provide the essential framework for such an explanation.

BIOCHEMISTRY

Tools to study biochemistry: All students of life must have a fundamental

understanding of general chemistry, organic chemistry and biology.

Know chemical structures and reactivities of molecules that participate in cellular reactions.

Know biological functions of cellular molecules. Know how all of the pieces and different chemical

reactions fit together.

Interweaving of the historical traditions

of biochemistry, cell biology, and genetics.

2. Biophysics - which applies the techniques of physics to study the structures of biomolecules.

3. Medical research - which increasingly seeks to understand disease states in molecular terms.

4. Nutrition - which has illuminated metabolism by describing the dietary requirements for maintenance of health.

5. Microbiology - which has shown that single-celled organisms and viruses are ideally suited for the elucidation of many metabolic pathways and regulatory mechanisms.

Biochemistry draws its major themes from:

1. Organic chemistry - which describes the properties of biomolecules.

8. Genetics - which describes mechanisms that give a particular cell or organism its biochemical identity.

7. Cell biology - which describes the biochemical division of labor within a cell.

6. Physiology - which investigates life processes at the tissue and organism levels.

Elements of Life

Up to 99+% of the human body is made of the elements C (9.5%), H (25.2%), O (63%) and N (1.4%).

Only 31 chemical elements occur naturally in plants and animals.

99% of the mass of the human body is made up of only six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus.

Every organic molecule contains carbon. Since 65-90% of each body cell consists of water (by weight), it is not surprising that oxygen and hydrogen are major components of the body.

Question

Their ability to form covalent bonds by electron-pair sharing.

What property unites H, O, C and N and renders these atoms so appropriate to the chemistry of life?

Bond Energy (kJ/mol)

H-H 436C-H 414C-C 343C-O 351

The elements of Life C, the hybridizer H, placeholder and water

builder O, the oxidizer and hydrogen

bonder N, protein builder Ca, the skeletizer

Fe, the O2 carrier Na,K depolarizers P, the energy carrier Cl, the neutralizer S, the linker Mg, Zn, Cu, Ni, Mo

enzyme coordinators

Oxygen (65%) Carbon (18%) Hydrogen (10%) Nitrogen (3%) Calcium (1.5%) Phosphorus (1.0%)

Magnesium (0.05%)

Potassium (0.35%)

Sulfur (0.25%) Sodium (0.15%)

Copper, Zinc, Selenium, Molybdenum, Fluorine, Chlorine, Iodine, Manganese, Cobalt, Iron (0.70%)

Lithium, Strontium, Aluminum, Silicon, Lead, Vanadium, Arsenic, Bromine (trace amounts)

1. Proteins- these are polymers of amino acids linked by peptide

bonds.- they are also called polypetides.- they function as transport proteins, structural proteins,

enzymes, antibodies, cell receptors.

Biomolecules of Life

2. Nucelic acids- classified as RNA and DNA, are polymers of

nucleotides linked by phosphodiester bonds.

- the nucleotide sequence in these polymers spells out the genetic information that directs growth, development and reproduction.

3. Carbohydrates- also known as polysaccharides which are polymers of

monosaccharides.- function as storage sources of energy in plants (starch)

and animals (glycogen) and as structural elements in plants.

- function as storage sources of energy in plants (starch) and animals (glycogen), as structural elements in plants, supply carbon for synthesis of other compounds and used in intercellular communications..

4. Lipids- storage of energy in the form of fat

- responsible for the integrity of cellular membranes (phospholipids), synthesis of hormones and vitamins, and act as insulator (thermal blanket).

Living things are composed of lifeless molecules. When these molecules are considered individually, they are found to conform to all the physical and chemical laws that describe the behavior of inanimate matter.

But when put together in a particular manner, this collection of lifeless molecules start to exhibit the different attributes of life.

What is Life?

Hard to define!

Necessary Properties highly organized and complicated

- all organisms are consist of one or more cells (atoms connect to form molecules, molecules make organelles, and organelles make cells. Cells make up tissue, tissues organized into organs, and organs into organ systems.

Let’s list some of its properties.

uses energy- all organisms acquire and use energy to

perform many kinds of work.

sensitive (interacts with its environment)

- plants grow toward light, an animal’s pupils dilate in darkness, amoeba and paramecia move toward food.

evolutionary adaptation- all organisms interact with the environment and other organisms in ways that

influence their survival to better adapt to their environment. homeostasis

- all organisms maintain ‘relatively’ constant internal conditions like ion concentration, body fluid, temperature, glucose in the bloodstream, blood pH, blood pressure, etc.

metabolism- ability to change substances into different substances to get energy.

excretion- removal of waste products

grows and develops

Likely (but maybe not be necessary) Properties

- normally, all forms of life must grow to allow development and reproduction

reproduces- heriditary molecules (RNA and DNA) ensures production of offspring similar to

previous generation. mutates and evolves

- long term adaptation, new forms of life are formed from life itself

Requirements for Life

1. Energy (need food to function)a. Autotrophs = make their own food (plants are autotrophs)

b. Heterotrophs = cannot make their own food (animals, people, dogs, lizards, are heterotrophs).

2. Water – all living things need water to survive.

3. Living Space – need a place to get food, water, and shelter.

4. Homeostasis = Stable Internal Conditions – so when the temperature gets too cold or hot, or too wet or dry where they live, their body still stays the same inside.

The Cell

All living organisms on earth are made of cells except viruses. The smallest unit that is capable of life.

one-celled organism, Bacteriamulticellur organism, Human

(at least 1014 cells)

There are many different types of cells that are usually highly specialized. The differences could be according to shape and function.

Examples of Cells

Amoeba Proteus

Plant Stem

Red Blood Cell

Nerve Cell

Bacteria

All cells are relatively small. They vary in length from 2 m to 30 m.

Prokaryotic Cell

Do not have structures surrounded by membranes Few internal structures No nucleus

• Nucleoid region contains the DNA

• Contain ribosomes (no membrane) to make proteins in their cytoplasm

• Cell membrane and cell wall

Contain organelles such as a nucleus surrounded by membranes

Eukaryotic Cell (Animal)

Most living organisms

Contain 3 basic cell structures:• Nucleus• Cell Membrane• Cytoplasm with organelles

“Typical” Animal Cell

Eukaryotic Cell (Plant)

• Nucleus• Cell Membrane• Cytoplasm with

organelles

Contain 3 basic cell structures:

“Typical” Plant Cell

Functions of Organelles

Cell Membrane

Double membrane surrounding the chromosomes and the nucleolus. Pores allow specific communication with the cytoplasm. The nucleolus is a site for synthesis of RNA making up the ribosome

A lipid/protein/carbohydrate complex, providing a barrier and containing transport and signaling systems. (Serves as security guards or gate keeprs. Decides what can enter or leaves the cell. It lets in useful substances and lets out waste.)

Nucleus

(Serves as the control center. All the activities inside the cell are controlled by instructions which comes from the nucleus.)

Cell wallPlants have a rigid cell wall in addition to their cell membranes

Cytoplasmenclosed by the plasma membrane, liquid portion called cytosol and it houses the membranous organelles.

Surrounded by a double membrane with a series of foldscalled cristae. Functions in energy production through metabolism. Contains its own DNA, and is believed to have originated as a captured bacterium.

Mitochondrion

(Serves as the power house of the cell. The mitochondira releases energy from food.)

Chloroplasts (plastids)Surrounded by a double membrane, containing stacked thylakoid membranes. Responsible for photosynthesis, the trapping of light energy for the synthesis of sugars. Contains DNA, and like mitochondria is believed to have originated as a captured bacterium.

Endoplasmic reticulum (RER)

A network of interconnected membranes forming channels within the cell. Covered with ribosomes (causing the "rough" appearance) which are in the process of synthesizing proteins for secretion or localization in membranes.(Serves as the construction team of the cell.)

A series of stacked membranes. Vesicles (small membrane surrounded bags) carry materials from the RER to the Golgi apparatus. Vesicles move between the stacks while the proteins are "processed" to a mature form. Vesicles then carry newly formed membrane and secreted proteins to their final destinations including secretion or membrane localization.

Golgi body

(Serves as the assembly and storage point of the cell. Some of the substances made in the cells are assembled and stored in the Golgi body.)

A membrane bound organelle that is responsible for degrading proteins and membranes in the cell, and also helps degrade materials ingested by the cell.

Lysosymes

(Serves as the waste disposal unit of the cell. The lysozomes eat up waste materials and old worn out parts of the cell.)

Membrane surrounded "bags" that contain water and storage materials in plants.

Vacuoles

Peroxisomes or MicrobodiesProduce and degrade hydrogen peroxide, a toxic compound that can be produced during metabolism.

Arrays of protein filaments in the cytosol. Gives the cell its shape and provides basis for movement. E.g. microtubules and microfilaments.

Cytoskeleton

Cell-Factory Analogy

Assignment

Purpose: To compare the structure and function of cells with a familiar system.

DIRECTIONS: You will create an analogy (comparison) for a cell using a factory.

Your analogy will include a (1) drawing or model where you label each part of the city/house/body/station and its corresponding cell part (organelle), and a (2) written description of each city/house/body/station part and how it is similar to its corresponding organelle.

Biomolecules in Cells

Biochemical Reactions

• Metabolism

Catabolism - degradation of fuel molecules and the production of energy for cellular function

- total sum of the chemical reaction happening in a living organism (highly coordinated and purposeful activity)

Anabolism – biosynthesis of small molecules to larger molecules which requires energy.

All biochemical reactions occur inside the cell and are catalyzed by enzymes.

Both anabolism and catabolism may occur simultaneously not only because they involve different enzymes but also because they ma be separated in their location within the cell.

FUNCTIONS OF METABOLISM1. Acquistion and utilization of energy.2. Synthesis of molecules needed for cell structure and functioning

(i.e., proteins, nucleic acids, lipids, etc.3. Removal of waste products.

• For example:catabolic

anabolic

the degradation of fatty acids to acetyl CoA occurs by way of exnzym located within the mitochondria, whereas the anabolic conversion of acetyl CoA to fatty acids occurs in the cytoplasm by way oif a separate system.

Metabolism generally occurs by orderly, stepwise, series or sequence of individual chemical reactions that are dependent on the basic laws of thermodynamics called as metabolic pathways.

Metabolic Pathway

An example of a simple metabolic pathway is the single step conversion of a precursor A to a given product B.

A Benzyme an enzymatic reaction

is reversible.

• Also called biochemical pathway, is a multistep reaction within a cell that is catalyzed by enzymes

In a multi-steps metabolic pathway, product B could become a substrate of the second reaction to yield product C and so on.

AE1

BE2

CE3

DE4

EE5

Product linear metabolic pathway E’s are enzymes B, C, D, E are intermediate substances also called metabolites.

AE1

B E3 FE6

GE9

HE12

Product 2

E2 CE5

DE8

EE11

Product 1

E4

IE7

JE10

KE13

Product 3

branched metabolic pathway

Primary Metabolic Pathway

A series of metabolism or biochemical reactions that encompasses reactions involving primary compounds which are formed as part of the normal anabolic and catabolic processes of plants and animals.

Primary metabolites are compounds commonly produced from primary metabolic pathways such as proteins, carbohydrates, lipids, nucleic acid that are directly used for growth and devlopment.

Examples: Glycolysis Citric Acid Cylce

Electron Transport Chain Oxydation of Fatty Acids

Absence of primary metabolites will cause cells and the whole organism to die.

GLYCOLYSIS reverse steps not shown

Secondary Metabolic Pathway

A metabolism of secondary compounds or secondary metabolites other than primary compunds.

antibiotics

A compound is classified as secondary metabolite if it does not seem to to directly function in the processes of growth and devlopment of the animal or plant.

Even though secondary compounds are a normal part of the metabolism of an organism, they are often produced in specialized cells and tend to be more complex than primary compounds.

Examples of secondary metabolites

alkaloids

Even though thousands of reactions sound very large and complex inside a tiny cell:

1. The type of reactions are small.2. Mechanisms of biochemical reactions are simple.3. Reactions of central importance (for energy production and

synthesis and degradation of major cell components) are relatively few in number.

Frequent reactions encountered in biochemical processes:

1. Nucleophilic substitution• one atom or group of atoms substituted for another.

2. Elimination reactions• double bond is formed when atoms in a molecule is removed.

3. Addition reactions• two molecules combine to form a single product.• hydration reactions - water added to alkene > alcohol

(common addition reaction).

4. Isomerization reactions• involve intramolecular shift of atoms or groups

5. Oxidation-Reduction (redox) reactions• occur when there is transfer of electron from a donor to an

electron acceptor.

6. Hydrolysis reactions• cleavage of double bond by water.

MATTER:PRODUCED IN BIG BANG (H & He) AND STARS (HEAVIER

ELEMENTS) ARE CERTAIN ELEMENTS NEEDED? STABLE ENERGY SOURCE:

LOW MASS MAIN SEQUENCE STARS (OR SOMETHING ELSE?) PROTECTED ENVIRONMENT:

PLANETARY OR LUNAR SURFACESPLANETARY OR LUNAR INTERIORSTHICK PLANETARY OR LUNAR ATMOSPHERES

CHEMICAL SOLVENT (LIQUID): WATER (OR SOMETHING ELSE?) APPROPRIATE TEMPERATURE RANGE: NEEDED TO KEEP THE SOLVENT LIQUID (APPROXIMATELY 0 TO

100o C IF WATER IS THE LIQUID SOLVENT)IF IT’S TOO HOT, COMPLEX STRUCTURES ARE BROKEN APARTIF IT’S TOO COLD, INTERACTIONS ARE TOO SLOW

Requirement for Life

Secondary metabolism:Metabolism of secondary compounds, defined simply as compounds other than primary compounds. A compound is classified as a secondary metabolite if it does not seem to directly function in the processes of growth and development. Even though secondary compounds are a normal part of the metabolism of an organism, they are often produced in specialized cells, and tend to be more complex than primary compounds. Examples of secondary compounds include antibiotics, and plant chemical defenses such as alkaloids and steroids.

MetaCyc (www.metacyc.org)Taiz, Lincoln, and Eduardo Zeiger. "Surface Protection and Secondary Defense Compounds." Plant Physiology. New York: Benjamin/Cummings Publishing Company, Inc., 1991: 320-345.[item in sorceforge, should be readdressed via sourceforge]

Secondary metabolism:Processes that result in many of the chemical changes of compounds that are not required for growth and maintenance of cells, and are often unique to a taxon. In multicellular organisms secondary metabolism is generally carried out in specific cell types, and may be useful for the organism as a whole. In unicellular organisms, secondary metabolism is often used for the production of antibiotics or for the utilization and acquisition of unusual nutrients.

MetaCyc (www.metacyc.org)Taiz, Lincoln, and Eduardo Zeiger. "Surface Protection and Secondary Defense Compounds." Plant Physiology. New York: Benjamin/Cummings Publishing Company, Inc., 1991: 320-345.[item in sorceforge, should be readdressed via sourceforge]

Metabolic Pathway Examples Glycolysis (Carbohydrate Metabolism): Glucose

+ 2 ADP + 2 Pi + 2 NAD+ 2 Pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O

Activation and Transport of Fatty Acids (Lipid Metabolism): Fatty Acid + ATP + Coenzyme A Fatty Acyl-CoA + Pyrophosphate + AMP + H+

Cholesterol Biosynthesis 1 (Lipid Metabolism): 6 Acetyl-CoA + 6 Acetoacetyl-CoA + 14 NADPH + 14 H+ + 5 H2O + 18 ATP + O2 Lanosterol + 14 NADP+ + 12 CoA-S-H + 18 ADP + 6 Pi + 4 PPi + 6 CO2

Shikimate Pathway (Amino Acid Metabolism): D-Erythrose-4-phosphate + 2  Phosphoenoylpyruvate + NAD+ + NADPH + ATP Chorismate + NADH + NADP+ + ADP + 4 Pi

Metabolic Pathway (Glycolysis)

Glucose + 2 ADP + 2 Pi + 2 NAD+ Glucose + 2 ADP + 2 Pi + 2 NAD+ 2 Pyruvate + 2 ATP + 2 NADH 2 Pyruvate + 2 ATP + 2 NADH + 2 H+ 2 H++ + 2 H + 2 H22OO

Main Players

Enzymes: polymers of amino acids that act as catalysts that regulate speed of many chemical reactions in the metabolism of living organisms; ex. Phosphoglucoisomerase, aldolase

Metabolites: substance involved or by-product of metabolism; ex. erythrose 4-phosphate, sedoheptulose 7-phosphate

Protein Carbohydrates Lipids

Amino Acids

.

RibosomesProtein and RNA complex responsible for protein synthesis

Smooth endoplasmic reticulum (SER)A network of interconnected membranes forming channels within the cell. A site for synthesis and metabolism of lipids. Also contains enzymes for detoxifying chemicals including drugs and pesticides.

Golgi apparatusA series of stacked membranes. Vesicles (small membrane surrounded bags) carry materials from the RER to the Golgi apparatus. Vesicles move between the stacks while the proteins are "processed" to a mature form. Vesicles then carry newly formed membrane and secreted proteins to their final destinations including secretion or membrane localization.

Primary (1°) Metabolism- Construct common biological macromolecules from simple building blocks found within every cell

- Typically a process of polymerization, stringing monomers together into a macromolecule that performs a cellular function

sugars polysaccharides

amino acids proteins

fats phospholipid bilayers

- Block production: cell dies (primary metabolites are essential)

Metabolism and Energy Production

Citric Acid CycleElectron Transport ChainATP Energy from GlucoseOxidation of Fatty Acids

Metabolic Pathways for Amino Acids

Outer membrane of cell that controls movement in and out of the cell

Double layer

Cell Membrane

Cell Wall Most commonly

found in plant cells & bacteria

Supports & protects cells

http://library.thinkquest.org/12413/structures.html

Inside the Cell

Nucleus Directs cell activities Separated from cytoplasm by nuclear

membrane Contains genetic material - DNA

Nuclear Membrane Surrounds

nucleus Made of two

layers Openings allow

material to enter and leave nucleus

http://library.thinkquest.org/12413/structures.html

Chromosomes In nucleus Made of DNA Contain

instructions for traits & characteristics

http://library.thinkquest.org/12413/structures.html

Nucleolus Inside nucleus Contains RNA to

build proteins

http://library.thinkquest.org/12413/structures.html

Cytoplasm Gel-like mixture Surrounded by cell membrane Contains hereditary material

Endoplasmic Reticulum Moves materials around in cell

Smooth type: lacks ribosomes

Rough type (pictured): ribosomes embedded in surface

http://library.thinkquest.org/12413/structures.html

Ribosomes Each cell contains

thousands Make proteins Found on

ribosomes & floating throughout the cell

http://library.thinkquest.org/12413/structures.html

Mitochondria Produces energy through

chemical reactions – breaking down fats & carbohydrates

Controls level of water and other materials in cell

Recycles and decomposes proteins, fats, and carbohydrates

http://library.thinkquest.org/12413/structures.html

Golgi Bodies Protein 'packaging

plant' Move materials

within the cell Move materials out

of the cell

http://library.thinkquest.org/12413/structures.html

Lysosome

Digestive 'plant' for proteins, fats, and carbohydrates

Transports undigested material to cell membrane for removal

Cell breaks down if lysosome explodes

http://library.thinkquest.org/12413/structures.html

Vacuoles Membrane-bound

sacs for storage, digestion, and waste removal

Contains water solution

Help plants maintain shape

http://library.thinkquest.org/12413/structures.html

Chloroplast Usually found in

plant cells Contains green

chlorophyll Where

photosynthesis takes place

http://library.thinkquest.org/12413/structures.html

What is Life Made of? Physical and Chemical sciences

alone may not completely explain the nature of life, but they at least provide the essential framework for such an explanation.

All students of life must have a fundamental understanding of organic chemistry and biology

Cell Structure

BOTTOM LINE:THE ELEMENTS THAT MAKE UP TERRESTRIAL

LIVING ORGANISMS ARE VERY COMMON IN STARS AND IN THE INTERSTELLAR MATERIAL FROM WHICH STARS AND PLANETS ARE FORMED.

IN LIVING THINGS, THE ATOMS OF THESE ELEMENTS ARE ORGANIZED IN ORGANIC MOLECULES, MANY OF WHICH ARE LARGE AND COMPLEX.

BASIC FACTS ABOUT LIFE ON EARTHLIVING ORGANISMS ON EARTH ARE MADE OF CELLS.

EXCEPTION: VIRUSES

A CELL IS TINY DROP OF WATER AND VARIOUS ORGANIC MOLECULES, SURROUNDED BY A MEMBRANE. SOME CELLS CONTAIN CERTAIN STRUCTURES, TO BE DISCUSSED LATER. SOME ORGANISMS (BACTERIA, FOR EXAMPLE) ARE SINGLE-CELLED, AND OTHER ORGANISMS (HUMANS, FOR EXAMPLE) ARE MULTICELLULAR. A CELL CAN DIVIDE, RESULTING IN TWO CELLS.

Bio-molecules Just like cells are building blocks of tissues likewise molecules are

building blocks of cells.

Animal and plant cells contain approximately 10, 000 kinds of molecules (bio-molecules)

Water constitutes 50-95% of cells content by weight.

Ions like Na+, K+ and Ca+ may account for another 1%

Almost all other kinds of bio-molecules are organic (C, H, N, O, P, S)

Infinite variety of molecules contain C. Most bio-molecules considered to be derived from hydrocarbons.

The chemical properties of organic bio-molecules are determined by their functional groups. Most bio-molecules have more than one.

Major Classes of small Bio-molecules 1. Amino

acids:

• Building blocks of proteins.

• 20 commonly occurring.

• Contains amino group and carboxyl group function groups (behavioral properties)

• R Group (side chains) determines the chemical properties of each amino acids.

• Also determines how the protein folds and its biological function.

• Individual amino acids in protein connected by peptide bond.

• Functions as transport proteins,

structural proteins, enzymes, antibodies, cell receptors.

Sugars

Carbohydrates most abundant organic molecule found in nature. Initially synthesized in plants from a complex series of reactions involving photosynthesis. Basic unit is monosaccharides. Monosaccharides can form larger molecules e.g.

glycogen, plant starch or cellulose.

Functions Store energy in the form of starch (photosynthesis

in plants) or glycogen (in animals and humans). Provide energy through metabolism pathways and

cycles. Supply carbon for synthesis of other compounds. Form structural components in cells and tissues.

Intercellular communications

Fatty acids Are monocarboxylic acid contains even number C atoms

Two types: saturated (C-C sb) and unsaturated (C-C db)

Fatty acids are components of several lipid molecules.

E,g. of lipids are triacylglycerol, streiods (cholestrol, sex hormones), fat soluble vitamins.

Functions Storage of energy in the form of fat Membrane structures Insulation (thermal blanket) Synthesis of hormones

Energy for Cells Living cells are inherently unstable.

Constant flow of energy prevents them from becoming disorganized.

Cells obtains energy mainly by the oxidation of bio-molecules (e- transferred from 1 molecule to another and in doing so they lose energy)

This energy captured by cells & used to maintain highly organized cellular structure and functions

How do complex structure of cells maintain high

internal order? 1. Synthesis of bio-molecules

2. Transport Across Membranes- Cell membranes regulate the passage of ions and

molecules from one compartment to another.

3. Cell Movement- Organised movement- most obvious characteristics of

living cells. The intricate and coordinated activities required to sustain life require the movement of cell components.

4. Waste Removal- Animal cells convert food molecules into CO2, H20 & NH3.

If these not disposed properly can be toxic.

Thank you for your indulgence!

Metabolic Pathway Examples Glycolysis (Carbohydrate Metabolism): Glucose

+ 2 ADP + 2 Pi + 2 NAD+ 2 Pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O

Activation and Transport of Fatty Acids (Lipid Metabolism): Fatty Acid + ATP + Coenzyme A Fatty Acyl-CoA + Pyrophosphate + AMP + H+

Cholesterol Biosynthesis 1 (Lipid Metabolism): 6 Acetyl-CoA + 6 Acetoacetyl-CoA + 14 NADPH + 14 H+ + 5 H2O + 18 ATP + O2 Lanosterol + 14 NADP+ + 12 CoA-S-H + 18 ADP + 6 Pi + 4 PPi + 6 CO2

Shikimate Pathway (Amino Acid Metabolism): D-Erythrose-4-phosphate + 2  Phosphoenoylpyruvate + NAD+ + NADPH + ATP Chorismate + NADH + NADP+ + ADP + 4 Pi

Year

Interweaving of the historical traditions

of biochemistry, cell biology, and genetics.

Proteins were thought to carry genetic information

1828

1897

1944

Miescher discovered DNA

Living things are composed of lifeless molecules. When these molecules are considered individually, they are found to conform to all the physical and chemical laws that describe the behavior of inanimate matter.