Biochemistry

Review

Atoms- the building blocks of matter

Nucleus- the center of an atom Proton-positively charged

particle in the nucleus Neutron-neutral particle in

the nucleus of the atom Electron- negatively

charged particle outside the nucleus

More Review

There are many chemical Rxn’s taking place in your body

Chemical reactions are when atoms or groups of atoms reorganize Bonds are broken and reformed during

the process

Ugh… More review

An element is a pure substance that can’t be broken down into another substance All known elements are located on the

periodic table Isotopes- same number of protons

different number of neutrons May be radioactive Carbon 12 v. Carbon 14

Still reviewing…..

Compounds- one or more elements combining to form a new substance Always found in certain ratios (H2O)

Chemically and physically different from the elements it consists of (H or O goes boom)

Can’t be broken into simpler compounds physically

Can be broken down chemically (electrical current and H2O)

You should know this….

Chemical bonds hold the elements of a compound together

Covalent bond Shared electrons STRONG BONDS Form molecules

Still on bonding…..

Ions & Ionic Bonding Atoms take or give up

electrons The resulting ion has

either a + or – charge▪ NaCl Na + Cl-

Used to transmit signals in cells

Electrolytes Held together by

electrostatic forces Disassociate in water

Energy and Rxn’s

Activation Energy- minimum amount of energy for a reaction to take place A candle won’t burn

unless the wick is lit Flame (energy)

provides activation energy

Enzymes

Enzymes are biological catalysts They lower the activation energy

needed for a reaction to proceed Most reactions in the human body need

more energy than 37 0C can provide Substrate- what the enzyme works on Active Site- part of the enzyme

perfectly matched to the substrate Like a lock and key

Many things effect enzymes Temperature- too high/low they don’t work pH – too high /low they don’t work▪ Pepsin works best at a pH of 2. Where is it in your

body?▪ What pH do most enzymes work best at?

Denature- the structure of the enzyme is permanently damaged and it will no longer work Frying an egg

Water

Water is H2O It is polar

The oxygen has a slight – charge The hydrogen has a slight + charge

Acids and Bases

Most solutes can dissolve in water Acids release H+ ions Bases release OH- ions Measured on the pH Scale

Organic Chemistry

All Biological elements contain carbon Organic molecules contain carbon

(CO2 is the exception) Carbon is special:

It can bond with 4 different elements It can bond with many different

carbons Carbon can form many shapes

Chains, branches, and rings

Biochem

Macromolecules- large organic molecules

Polymers- long chains of repeating units called monomers Held together by covalent bonds Cellulose, starch, DNA, and proteins are

all polymers

4 Major Macromolecules

Macromolecule

Function

Lipids •Stores Energy•Provides Steroids•Waterproof coatings

Proteins •Transports substances•Enzymes•Provides structural support•Provides hormones

Nucleic Acids

•Stores and communicates genetic information

Carbohydrates

•Stores Energy•Provides structural support

Carbohydrates

Carbohydrates – carbon, hydrogen, and oxygen

Monosaccharide (monomer)- simple sugars Glucose

Disaccharide- 2 simple sugars bonded Sucrose

Polysaccharide-polymers of sugars Cellulose, starch, glycogen

Lipids

Lipids are mostly made of carbon and hydrogen Monomer – fatty acids

Triglyceride-type of lipid Liquid in plants (oil) Solid in animals (butter)

Saturated vs. Unsaturated Fats

Saturated Can not bind to any

more H Solid

Unsaturated Have a double bond

and a kink liquid

Phospholipids

Amphipathic- Have a polar head Non-polar tail

Component of cell membranes

Biological Barriers

Steroids – type of lipid

Cholesterol- makes cell membranes leaky

Estrogen- female hormone

Testostone- male hormone

Structure of Proteins

Proteins are polymers of amino acids (monomer) Amino acids are made of carbon, hydrogen,

oxygen, nitrogen and sometime sulfur

Amino Acids

There are only 20 amino acids

All proteins are made out of different combinations of amino acids

Amino acids covalently bond to each other

Protein Structure

Amino acids fold into a 3-D shape α-helix β-pleated sheet

3-D shape held together by hydrogen bonding

If the shape changes the protein does not function