Basic cellular chemistry

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Basic cellular chemistry

What is to be hoped is a review of basic chemical principles

Atomic structure

Atoms:

Electrons, protons, neutrons, isotopes, ions

Chemical bonds

Ionic, covalent

Ionic bonds : electrons exchanged

Covalent bonds : electrons shared

Reactions & Equilibrium

Chemical equilibrium

Mass cannot be created nor destroyed and therefore when chemical reactions are written they have to be balanced in both kind and number of molecules :

2H

2

+ O

2

2H

2

O

2H

2

O

2

2H

2

O + O

2

Equilibrium : starting materials (reactants) and ending materials (products) go back and forth and are in equilibrium.

Equilibrium may favor the reactants or the products

Water

H and O covalently bound creates a polar molecule : partially positive and negative on opposites sides

These partial charges cause the molecules to “stick” to each other

Acid / base chemistry

Water can also dissociate into ions : H

+

and OH

-

Acids : chemicals contributing H +

Bases : chemicals contributing OH

-

Acids and bases mixed together produce salts

Acid / bases measured with pH scale pH 0 – 14 : 7= neutral

Redox reactions

In some chemical reactions, electrons may be exchanged between reactants : oxidation/reduction reactions (redox)

Oxidation : the loss of elections

Reduction : the gain of electrons

The two reactions are always coupled together

Simple organic chemistry

Chemistry of carbon compounds

Compounds containing carbon and hydrogen are organic

Compounds containing only carbon and/or oxygen are inorganic

Recurring groups of atoms have the same properties

Alcohols, aldehydes, ketones, carboxylic acids, amines, sulfhydryl

General Biochemistry

Four principle types of compounds found in living cells : macromolecules

Definitions, functions, examples

Carbohydrates

Simple sugars , polysaccharides

Proteins

Strings of amino acids

Protein structure :

Primary : aa sequence

Secondary : chain folding : alpha helix, beta sheet

Tertiary : complex 3-D structure

Quaternary : subunit orientation

Lipids

Fatty acids

Triglycerides

Phospholipids

Cyclic fatty acids

Nucleotides and Nucleic Acids

Nucleotides : bases, sugars and phosphates

Energy exchange : ATP

Electron exchange : NAD , FAD

Nucleic acids : polymers of nucleotides

DNA

RNA

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