Biological molecules

BIOLOGICAL MOLECULES

Carbohydrates, Lipids, Proteins, and Nucleic Acids

Is it made of carbohydrates?

CARBOHYDRATES

CARBOHYDRATES Organic compounds composed of carbon,

hydrogen, and oxygen in a 1:2:1 ratio.A carbohydrate with 6 carbon atoms would

have…

______ hydrogen atoms and ______ oxygen atoms 12 6

Source of ENERGY

Structural components of cells

MONOSACCHARIDES Monomer of carbohydrate (simple

sugar)

Most have 6 carbon atoms

Most common:1) Glucose (main source of energy)

2) Fructose (found in fruits)

3) Galactose (found in milk)

ISOMERS

Glucose, fructose, and galactose have the same chemical formula.

C6H12O6

Same formula but different structural forms.

DISACCHARIDES AND POLYSACCHARIDES Disaccharide: two monosaccharides

bond to form a double sugar.Example: sucrose

Polysaccharide: complex molecule composed of three or more monosaccharides.

POLYSACCHARIDES IN ANIMALS AND PLANTS Glycogen: animals store glucose in the

form of the large, complex molecule – glycogen

Starch: plants store glucose molecules in the form of starch.

Cellulose: large polysaccharide made by plants, which provide strength and rigidity to plant cells.

WHITE VS. WHOLE GRAIN

WHITE VS. WHOLE GRAIN

White bread is a simple carbohydrate (little nutritional value, digested more quickly, converted to fat more quickly)

Whole grain bread is a complex carbohydrate (high in fiber, vitamins and minerals, provide more energy, digested slowly)

LIPIDS

LIPIDS Large organic molecules

Nonpolar – do NOT dissolve in water

Include phospholipids, triglycerides, waxes, steroids

Higher ratio of carbon and hydrogen to oxygen than carbohydrates…. More C-H bonds

Store more energy per gram than most other organic compounds

FATTY ACIDS

Hydrocarbon End

C-HNonpolar

Hydrophobic

Carboxyl End-COOHPolar

Hydrophilic

Saturated: Each carbon atom is single-bonded to 4 other atoms; straight chain; molecules are close together; solid at room temperature

Unsaturated: Double bonds in the C chain; kinked chain; molecules are farther apart; liquid at room temperature

TYPES OF FATTY ACIDS: SATURATED VS UNSATURATED http://www.youtube.com/watch?v=

ESPNqKUluRs

Let’s list some more differences in the form and function of fatty acids

TYPES OF LIPIDS MADE OF FATTY ACIDSTriglycerides (FATS)

3 fatty acids molecules joined to 1 glycerol

Saturated triglycerides are composed of saturated fatty acids (butter, other dairy products, fat from red meat)

Unsaturated triglycerides are composed of unsaturated fatty acids (mostly found oils and in plant seeds)

TYPES OF LIPIDS MADE OF FATTY ACIDS

Phospholipids

Glycerol is connected to 2 fatty acid molecules and a phosphate group.

The plasma membrane of the animal and plant cells are composed of a phospholipid bilayer.

TYPES OF LIPIDS MADE OF FATTY ACIDSWaxes

Composed of a long fatty acid chain and a long alcohol chain.

Waterproof and provide protection.

Found on the surface of plants and in the ear canals of many animals (including humans).

STEROIDS NOT composed of fatty acids

Four fused carbon rings which are attached to other functional groups

Cholesterol (found in the cell and plasma membrane)

Hormones such as testosterone and estrogen

PROTEINS

Is it made of Proteins?

PROTEINS ~ WHAT ARE THEY? Organic molecules compose of

hydrogen, carbon, oxygen and NITROGEN

Monomers = AMINO ACIDS

Examples: HairHornsSkinMusclesENZYMES (to learn more about later!)

AMINO ACIDS (AA) 20 different AA

Central carbon, C, that is covalently bonded to 4 other groups1. Hydrogen = blue2. Carboxyl (-COOH) = green3. Amine (-NH2) = yellow4. R group = red (varies in each AA and

determines the AA’s form and function

AA can also be illustrated as a ball

DIPEPTIDES AND POLYPEPTIDES

Dipeptide: two amino acids bond Polypeptides: long chains of amino acids

(made up of 1 or more dipeptide) Making proteins: what builds them?

Reaction: condensation or hydrolysis

Water is released or used

DIPEPTIDES AND POLYPEPTIDES Some proteins are very large, some are

small. Protein shape:

Influences its function (form and function)Shape can be influenced by factors like

temperature and solvent) … for example, egg white is clear when it is uncooked, and white when it is cooked

ENZYMES RNA or protein molecules that act as

biological catalystsCatalyst – speeds up the reaction by

lowering the activation energy Essential for cellular function Each Enzyme bonds with a specific

Substrate for form the Active Site

HOW DO ENZYMES WORK Speed up reactions – how????

Enzyme bonds to substrate and the enzyme shape changed slightly

The chemical bonds in the substrate are weakened

Lowers the activation energy

What happens after the reaction? Enzyme releases the products Enzyme is unchanged…

BUT changes in temperature and pH can change the enzyme (denature it) and it may not function properly or at all

NUCLEIC ACIDS

NUCLEIC ACIDS ~ SOURCE OF THE INFORMATION Large and complex biological molecules

Store and transfer important information in the cell

Genetic Code

Two types – both are polymers 1. DNA - DeoxyriboNucleic Acid 2. RNA - RiboNucleic Acid

DNA is transcribed into RNA, which is translated into PROTEINS

NUCLEIC ACIDS ~ STRUCTURE Each nucleotide is made of:

a phosphate group, a five carbon sugar, and a ring-shaped nitrogen base

Nitrogen basesA - AdenineC – CytosineG – GuanineT – ThymineU - uracil