Chapter TWO. Biochemistry

Question 1

Inorganic compounds

Answer 1

Lack carbon and are structurally simple
ex. water, salts, acids and bases

Question 2

Organic compounds

Answer 2

always contain carbon (usually hydrogen). are formed by covalent bond (ex. carbohydrates, lipids, proteins, nucleic acids, and adenosine triphosphate/ATP)

Question 3

Water

Answer 3

Most abundant and important inorganic compounds i all living organisms

Question 4

Water

Answer 4

Most abundant and important inorganic compounds in all living organisms

Question 5

Important properties in water

Answer 5

• high heat capacity
• high heat of vaporization
• polar solvent (water can dissolve most things) (holds ionic and covalent bonds)
• formed during dehydration synthesis reactions and required in hydrolysis reactions
• cushioning and lubricating effect

Question 6

Salts

Answer 6

Dissociate into positive and negative ions (neither of which is H+ or OH-) when dissolved in water

Question 7

Acids

Answer 7

Dissociate into 1 or more hydrogen ions (H+), and 1 or more negative ions.
(Also known as proton donors)

Question 8

Bases

Answer 8

Dissociate into 1 or more hydroxyl ions (OH-) and 1 or more positive ions.
(Also known as proton acceptors)

Question 9

The pH Scale

Answer 9

number from 0-14
- pH greater than 7 is acidic
- pH less than 7 is basic
- pH = to 7 is neutral
1 pH unit = to a 10X change in H+ concentration
ex. pH of 6 has 100X more H+ than the pH of 8

Question 10

Organic Compounds

Answer 10

• comprise 38-40% of total body mass.
• contain Carbon, Hydrogen, and other functional groups
• are built by joining monomers (small building blocks) together into polymers (macromolecules).
  ex. Lego blocks (building blocks)

Question 11

Carbon

Answer 11

• Atomic number = 6
• has 4 valence shell electrons so usually forms 4 covalent bonds with other elements

Question 12

Dehydration Synthesis

Answer 12

Monomers are joined by removal of OH from one monomer and removal of H from the other at the site of bond formation. (This allows them to share electrons to form a covalent bond)

Question 13

Hydrolysis

Answer 13

Monomers are released by the addition of water molecule, adding OH to one monomer and H to the other (AKA chemical breakdown of molecules due to water)

Question 14

Carbohydrates

Answer 14

• includes sugars, glycogen, starches, and cellulose
• composed of C, H, and O
• Are the main source of chemical energy for metabolism

Question 15

Monosaccharides

Answer 15

simples, with general formula CH2O ex. glucose

Question 16

Disaccharides

Answer 16

formed by a dehydration synthesis to join 2 monosaccs ex. sucrose

Question 17

Polysaccharides

Answer 17

large chains of many monosaccs joined together. ex. glycogen

Question 18

Isomers

Answer 18

Glucose, Fructose, Galactose

Question 19

Lipids

Answer 19

are Hydrophobic (water-fearing)
- composed of C, H, and O (but less O)
- nonpolar compounds (no soluble in water
- includes Triglycerides (fats and oils), phospholipids, and steroids

Question 20

Triglycerides (neutral fats)

Answer 20

• composed of glycerol and 3 fatty acid chains
• important for storage of energy, insulation, and shock absorption

Question 21

Phospholipids

Answer 21

• composed of glycerol, 2 fatty acids, and a phosphate group (polar)
• main component of membranes
• (hydrophilic - water loving)

Question 22

Steroids

Answer 22

• consists of 4 interlocking carbon rings with various side groups
• includes cholesterol and steroid hormones

Question 23

Proteins

Answer 23

• composed of C, H, O, and N (can also have sulfur and phosphorous)
• are polymers built from the 20 different amino acids

Question 24

Amino acids

Answer 24

are joined by peptide bonds (covalent bond) formed by dehydration synthesis

Question 25

Protein Structure (4 structural levels of proteins)

Answer 25

1. Primary structure: Linear sequence 2. Secondary structure: a-helix or B-pleated sheet 3. Tertiary structure: complex globular shape. (three-dimensional shape of polypeptide chain) 4. Quaternary structure: interaction of 2 or more polypeptides (arrangement of two or more polypeptide chains)

Question 26

How are proteins classified?

Answer 26

Structural (fibrous) or Functional (globular)

Question 27

Structural (fibrous)

Answer 27

- stable and insoluble in water - provide mechanical support and give strength

Question 28

Functional (globular)

Answer 28

- less stable, H-bonds break easily - are water soluble

Question 29

what happens to proteins if their environment changes

Answer 29

can denature and ceese to function

Question 30

Catalysts

Answer 30

Substance that increases weight of chemical reaction without being used up or altered in any way

Question 31

Nucleic Acids (large molecule)

Answer 31

- Composed of C, H, O, N, and P - are chains of nucleotides (long chains of building blocks/monomers)

Question 32

Nucleotide

Answer 32

Nucleotide = phosphate group + 5C sugar (pentose) + nitrogenous base

Question 33

Two kinds of Nucleic acids

Answer 33

- Deoxyribonucleic acid (DNA) - Ribonucleic acid (RNA)

Question 34

Deoxyribonucleic acid (DNA)

Answer 34

- double stranded polymer (ladder-like-shape), twisted into a double helix - sugar is deoxyribose - N-bases are A, T, C, and G - H bonds join N-bases ("rungs") - alternating sugar and phosphate molecules form the "uprights" of the ladder

Question 35

Ribonucleic acid (RNA)

Answer 35

- single nucleotide chain - sugar is ribose - N-bases are A, U, C, G (U replaces the T found in DNA)

Question 36

Several types of RNA (3)

Answer 36

rRNA, mRNA, tRNA (all involved in protein synthesis)