A&P Lecture 4 - Chemistry Comes Alive

Organic compounds contain

carbon

Organic compounds are..

1. Containing carbon

2. Covalently bonded

3. Large

Inorganic compounds do not…

contain carbon

Inorganic compounds are

water, salts, many acids and bases

2. salts

3. many acids and bases

High heat capacity

absorbs and releases large amounts of heat before changing temperature

High heat of vaporization

changing from a liquid to a gas requires large amounts of heat

Polar solvent properties

dissolves ionic substances, forms hydration layers around large, charged molecules, and serves as the body's major transport medium

Salts are

Inorganic compounds

Salts contain cations other than

H+

Salts contain anions other than

OH-

Salts are _____ and conduct electrical _____

1. electrolytes

2. currents

Acids release H+ and are therefore

proton donors

Bases release OH- and are

proton acceptors

Acidic solutions have higher H+ concentration and therefore

a lower pH

Alkaline solutions have lower H+ concentration and therefore a

higher pH

Neutral solutions have equal

H+ and OH- concentrations

Buffers are

Systems that resist abrupt and large swings in the pHof body fluids

Carbonic acid dissociates, reversibly releasing

bicarbonate ions and protons

The chemical equilibrium between carbonic acidand bicarbonate resists

pH changes in the blood

Molecules unique to living systems contain carbonand hence are

organic compounds

Organic compounds include

1. Carbohydrates

2. Lipids

3. Proteins

4. Nucleic Acids

Carbohydrates contain

carbon, hydrogen, oxygen

carbohydrates major function is to

supply a source of cellular food

Lipids contain C, H, O but the proportion of oxygen in lipids is less than in

carbohydrates

Triglycerides

Composed of three fatty acids bonded to a glycerol molecule

Phospholipids

modified triglycerides with two fatty acid groups and a phosphorus group

Steroids

flat molecules with four interlocking hydrocarbon rings

Eicosanoids

20 - carbon fatty acids found in cell membranes

Neutral fats

found in subcutaneous tissue and aroundorgans

Phospholipids

chief component of cell membranes

Fat-soluble vitamins

vitamins A, E, and K

Eicosanoids

prostaglandins, leukotriens, and thromboxanes

Lipoproteins

transport fatty acids and cholesterol in the bloodstream

Amino acids are

building blocks of protein containing an amino group and a carboxyl grou[

Protein structure is

composed of combinations of 20 types of amino acids bound together with peptide bonds

Structural level of proteins: Primary

amino acid sequence

Structural level of proteins: secondary

alpha helices or beta pleated sheets

Structural levels of proteins: tertiary

superimposed folding of secondary structures

Structural Levels of Proteins: Quaternary

polypeptide chains linked together in a specific manner

Fibrous proteins

Extended and strandlike proteins

Globular proteins

Compact, spherical proteins with tertiary and quaternary structures

Protein Denuaturation

Reversible unfolding of proteins due to drops in pH and/or increased temperature

Protein Denuaturation

Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature changes

Molecular Chaperones (Chaperonins)

Help other proteins to achieve their functional three-dimensional shape

Chaperonins maintain

folding integrity

chaperonins assist in

translocation of proteins across membranes

chaperonins promote

the breakdown of damaged or denatured proteins

Most enzymes are 1. ______ that act as biological 2. _______

catalysts

holoenzymes consist of

apoenzyme and cofactor

what is apoenzyme?

protein

enzymes are chemically

specific

enzymes are frequently named for

the type of reaction they catalyze

enzyme names usually end in

-ase

enzymes are

lower activation energy

Enzymes binds with

substrate

Product is formed at a lower

activation energy

during enzyme action,

product is released

Nucleic Acids

carbon, oxygen, hydrogen, nitrogen, and phosphorus

Nucleotide is composed of

a nitrogenous base, a phosphate group, and a pentose sugar

Five nitrogen bases contribute to the nucleotide structure

adenine, guanine, cytosine, thymine, and uracil

Two major classes

DNA and RNA

Deoxyribonucleic Acid (DNA)

Double-stranded helical molecule found in the nucleus of the cell

the DNA replicates itself before the cell divides, ensuring

genetic contuinity

DNA provides instructions for

protein synthesis

Ribonucleic Acid

Single-stranded molecule found in both the nucleus and the cytoplasm of a cell

RNA uses the nitrogenous base _____ instead of thymine

uracil

Three varieties of RNA

1. messenger

2. transfer

3. ribosomal

Adenosine Triphosphate (ATP)

Source of immediately usable energy for the cell

Adenine-containing RNA nucleotide with three phosphate groups