Unit 1, Part 2 Chemistry in the Body. Let’s talk Chemistry! But why? Food Medicine Your Body.

Unit 1, Part 2

Chemistry in the Body

Let’s talk Chemistry! But why?

• Food

• Medicine

• Your Body

Chemistry is all over in your body!

• There are THOUSANDS of chemicals in your body.

• All body processes involve chemistry!– Movement– Digestion– Metabolism– Respiration– Pumping of your heart– Nervous System signals

The Basics…

• Matter – anything that occupies space and has mass

• Three phases of matter– Solid: definite shape, definite volume– Liquid: definite volume, but not shape– Gas: neither a definite shape or volume

The Basics

• Physical Changes: Do not alter the basic nature of a substance (chemical formula)– EX: Bend, Cut, Dissolve, Phase Changes

• Chemical Changes: DO alter the composition of the substance – a new chemical formula is formed!– EX: Digestion of food by enzymes in the body,

Metabolism reactions

The Basics

• The atom: smallest particle that retains properties of a particular element– Proton: in nucleus, + charge– Neutron: in nucleus, no charge– Electron: orbitals, - charge, smallest– In neutral atom, # of protons = # of electrons

• Elements identified by number of protons• Bonding determined by number of valence

(outer) electrons

The Basics

• Compound: when two or more atoms combine chemically (ex: H2O)

• Ion: formed when an atom has lost or gained an electron– Positive ions formed when an electron is lost– Negative ions formed when an electron is

gained

– Common ions found in the body include Ca+2, Na+, K+, H+, OH-, Cl-

The Basics

• Chemical reactions are when 2 or more chemicals combine to create new products

• Types of reactions include…– Synthesis (in the body, called anabolic)

• A + B AB

– Decomposition (in the body, called catabolic)• AB A + B

– Single Replacement• A + BC AC + B

– Double Replacement• AB + CD AD + CB

NOTE: anabolic and catabolic reactions in the

body are collectively called metabolism!

Which type of reactions are the following???

The Basics

• Acids vs. Bases– Acids

• Usually have H+ in the formula

• Release H+ into solution• pH less than 7

– Bases• Usually have OH- in the

formula• Release OH- into the

solution • pH greater than 7

Chemistry in the Body

• 96% of all elements in the human body are from 4 major sources– Oxygen (65%)– Carbon (18.5%)– Hydrogen (9.5%)– Nitrogen (3.2%)

• One of the most important of these is Carbon… (show video clip)

Chemistry in the Body

• Organic– Contains carbon– Ex: Carbohydrates, lipids, proteins, nucleic

acids

• Inorganic– No carbon– Ex: Water, salts, acids, bases

Important Organic Compounds

• CARBOHYDRATES– Contain carbon, hydrogen, and oxygen in a

1:2:1 ratio– Include sugars and starches– Act as a source of cellular fuel– Classified into 3 groups according to size

• Can be soluble in water

Important Organic Compounds• Monosaccharide

– Simple Sugar

– Usually used for energy source

– Examples include glucose, galactose, and fructose (isomers: all have formula of C6H12O6, but in different combinations & orientations)

Important Organic Compounds

– Other examples with 5 sugars are ribose and deoxyribose (found in RNA and DNA)

Important Organic Compounds

• In aqueous (water) solutions, monosaccharides will form ring structures

Important Organic Compounds

• Disaccharide– Two simple sugars (monosaccharides) are

joined by a dehydration synthesis (loss of water happens as molecules join)

– Includes sucrose (table sugar), lactose (milk sugar), and maltose

Important Organic Compounds

This shows a dehydration reaction – water will be produced as a product!

Important Organic Compounds

Important Organic Compounds• Polysaccharides

– long branching chains of linked simple sugars– Includes glycogen in animals, and starch &

cellulose in plants– Interesting tidbit: glucose needed for muscle

contraction is usually stored as glycogen

Important Organic Compounds• Both disaccharides and polysaccharides

can be broken down back into monosaccharides by a hydrolysis reaction (adding water in)

• Glucose is then commonly used in cellular respiration (C6H12O6 + O2 CO2 + H2O)

FYI…

• If we eat too many carbs, and our body doesn’t immediately need any ATP, dietary carbs are then converted to glycogen or fat and stored!

Important Organic Compounds

• LIPIDS– Contain carbon,

hydrogen, and oxygen• Carbon and

hydrogen outnumber oxygen

– All types are insoluble in water

Functions of Lipids in the Body

• Protection - pads organs• Insulation - prevents heat loss• Regulation – hormones• Structure - cell membrane component• Energy - storage in fat

Important Organic Compounds• Triglycerides (Neutral Fat)

– Constitutes 95% of the fat in the human body– Composed of three fatty acids bonded to a

glycerol molecule– Found in subcutaneous tissue and around

organs, used as fuel

Important Organic Compounds

• Again, fatty acid chains are added to the glycerol by a dehydration synthesis!

• The bonds along the fatty acid chain can be oxidized (broken) to release energy.

Important Organic Compounds

• Two types of Fatty Acid Chains…• Unsaturated

– less than the max # of hydrogens bonded to the carbons

– End up with double bonds between carbons– Healthier fats, such as olive oil, peanut oil, &

fish oils

Important Organic Compounds

• Saturated– Have the max # of hydrogens bonded to the

carbons– Only single bonds between carbons– Unhealthy fats, such as beef, pork, & butter

Important Organic Compounds• Phospholipids

– Composed of two fatty acids and a phosphorus group bonded to a glycerol molecule

– Chief component of cell membranes– Phosphorous end is polar (will mix with water),

while fatty acid end is nonpolar (not mix with water)

Important Organic Compounds

• Steroids– Flat molecules

with four interlocking hydrocarbon rings

– Found in cholesterol and certain hormones

Cholesterol

Testosterone Estrogen

FYI…• There are different kinds of

steroids!• Corticosteroids help with medical

issues like immunity, metabolism, and blood volume

• Sex steroids are the same thing at sex hormones – such as androgens and estrogens

• Anabolic steroids increase muscle mass and bone synthesis… the artificial form is usually derived from testosterone

Important Organic Compounds

• PROTEINS– Made of twisted chains of amino acids– 50% of organic matter in the body is composed of proteins– Can be soluble in water

Important Organic Compounds

Functions of Proteins Include:1. Storage: energy source2. Transport: hemoglobin; across

membranes3. Regulatory: hormones4. Movement: muscles5. Structural: membranes, hair, nails6. Enzymes: speed up cellular

reactions (catalysts)

Important Organic Compounds

• Amino Acids – the building blocks of proteins– Combination of Nitrogen,

Carbon, Hydrogen, and Oxygen

– All amino acids have the same basic structure, but a different R group attached!

– There are 20 different R groups found in humans

Structure of Amino Acids

•Amino acids have a central carbon with 4 things boded to it:

Amino group –NH2

Carboxyl group -COOHHydrogen -H

Side group -R

(has C & H present, and sometimes S or

O)

Amino

group

Carboxylgroup

R group

Side groups

Leucine

Serine

Have fun memorizing these when

you take Biochemistry in college!!!

Important Organic Compounds

• The joining of amino acids in a dehydration synthesis forms a peptide bond… the long chain that forms is the protein!

Important Organic Compounds• Protein shapes determine their function• If protein denatures (unravels) due to heat or

acidic pH levels, it will lose its function• There are four different structural levels that

contribute to the shape of a protein

JUST A THOUGHT…

With different combinations of the 20 amino acids, and the different shapes the molecules can take on, the potential number of different protein molecules is enormous!

Important Organic Compounds

• NUCLEIC ACIDS– Provide blueprint of

life – makes DNA– Includes a phosphate

group, sugar group, and base

Phosphategroup

Sugar(deoxyribose)

Nitrogenous base(A,G,C, or T)

Important Organic Compounds

– Nucleotide bases of DNA…• A = Adenine• G = Guanine• C = Cytosine• T = Thymine

Thymine (T) Cytosine (C)

Adenine (A)Guanine (G)

The two strands of

DNA are held together with

hydrogen bonding.

Important Organic Compounds

• RNA is different than DNA…– Sugar “Ribose”

used instead of “Deoxyribose”

– Uracil used instead of Thymine

Nitrogenous base(A,G,C, or U)

Sugar (ribose)

Phosphategroup

Uracil

Important Organic Compounds

• ADENOSINE TRIPHOSPHATE (ATP)– Chemical energy used

by all cells– Energy is released by

breaking high energy phosphate bond

+ energy