Cell Chemistry

Question 1

4 Major classes of compound composing cells

Answer 1

Polymer: Nucleic acids & Protiens
Monomer: Amino Acids, Saccharide, Nucleotide
Intracellular role: Enzymes, energy storage, structure
Fatty Acids: Fats & Lipids, energy storage, major structual component of membrane

Question 2

Characteristics of Water and consequences/benefit of pertaining

characteristic -> consequence

Answer 2

High Heat Capacity -> minimizes T changes
Higher density than ice -> ice forms on water surface
High heat of fusion -> organisms are protected from freezing at low T
Polarity of water -> Leads to hydrophobic interaction that confers stability
High Heat of vaporization -> land animals can cool themselves by surface evaporation

Most abundant molecule in organism, essential to life,

Question 3

General structure of amino acids and major classes

Examples of classes

Answer 3

Hydrophobic (Alanine)
Polar and Uncharged (Serine)
Charged (Lysine, Histidine)

Examples:

Question 4

Isoelectric Point

Answer 4

The pH point at which the amino acid has no net charge

Question 5

Which Amino Acid isomer is found in proteins and where to find the other

L & D

Answer 5

L is found in protein
D is found in cell walls of bacteria

Question 6

How do amino acids combine to form proteins

what bond

Answer 6

Peptide bonds

Question 7

Special property cysteine contributes to protein

Answer 7

Has a dissociation constant which allows it to make a sulfur bridge

Question 8

Important Forces involved in determining 3-D protein structure

Answer 8

Electrostatic
Hydrogen bonds
Hydrophobic forces
Covalent bond (disulfide bridges)

Question 9

Monosacchrides, Glucose, Fructose, and Sucrose

General formula

Answer 9

Glucose: C6H12O6
Fructose: C6H12O6
Sucrose: C5H10O5

Question 10

Glycosidic bond

Answer 10

A type of covalent bond that joins a carbohydrate (sugar) molecule to another group.

Question 11

General Properties of Polysaccharides (cellulose, starch, and glycogen) and roles in nature

Answer 11

Cellulose: Major component of wood and plant fiber. Hard to break down.
Starch: Used for energy storage in plants.
Glycogen: Is broken down to release glucose into the bloodstream to be used as fuel for cells

Question 12

General Formula of Fatty Acids and difference between saturated and unsaturated

Answer 12

CH3 – (CH2)n – COOH
Unsaturated fatty acids have C=C double bonds

Most double bonds are cis

Question 13

General Structure of Fats and how are they formed from Fatty Acids

Answer 13

Dehydration Synthesis

Question 14

3 Major Types of membrane lipids

Answer 14

Phospolipids (major class)
Glycolipids
Cholesterol

Question 15

Phospholipid general structure

Answer 15

Question 16

General structure of lipid bilayers

draw it using polar head - hydrophobic tail schematic

Answer 16

Question 17

Role of Lipid Bilayers in membrane formation and membrane composition

Answer 17

Lipid bilaters are formed in aqueous environments through hydrophobic interactions. Membrane forms a barrier between the inside and outside of cell.

Question 18

Integral and peripheral proteins

Answer 18

Integral: Extends partly or completly through membrane
Peripheral: Confined to membrane surface

Question 19

Explain the effects of lipid bilayers on membrane permeability

Water, neutral nonpolar, neutral polar, and charged molecules

Answer 19

Membrane is permeable to water and neutral nonpolar molecules
Less permeable to neutral polar molcules and impermeable to charged molecules

Question 20

Central Dogma

Answer 20

Question 21

Components of DNA and RNA

including bases utilized in them

Answer 21

DNA: Sugar, Base, Phosphate
Bases = A,T,G,C

RNA: Sugar, Base, Phosphate
Bases =A,T,U,C

Question 22

Difference between nucleotides and nucleosides

Answer 22

Nucleosides = base + sugar
Nucleotides = base + sugar + phosphate

Question 23

Importance of ATP

Answer 23

Energy

Question 24

How are Nucleotides combined to form DNA and RNA

Answer 24

Phospodiester bonds

3’ to 5’

Question 25

What is meant by complementary bases, double stranded, and antiparallel strands

in regard to DNA and RNA

Answer 25

Complementary: Two bases that pair together. A is complementary to T and C is complementary to G.
Double standed is the structure of DNA
The structure of DNA is antiparallel, which means there are to strands parallel to each other going in opposite directions.

Question 26

Chargaff’s Rule

What pairs to what: A, G, T, C, U

Answer 26

T = A
A = U
G ≡ C

A = U in RNA

Question 27

Basis of DNA replication

including leading and lagging strands

Answer 27

DNA unzips into 2 parts and splits with the cell. The leading strand it’s replicated continously in 3’ to 5’ direction. The lagging strand it’s replicated discontinously in short sections.

Question 28

Basis of Transcription

including concept of sense and antisense strands

Answer 28

Question 29

Know how to apply genetic code translation

Start Codon, End Codon and Direction (5’ and 3’)

Answer 29

Start Codon: AUG
mRNA is translated in the 5’ to 3’ direction
5’ (NH3+) –> 3’ (CO2-)

Another way to identify start codon is if you see CAT in the RNA chain

Question 30

Meaning of Constitutive and regulated genes

Answer 30

Constitutive are always being expressed but regulated are only expressed under certain necessary conditions in order to save cellular energy

Question 31

Types of Mutations

and Lethality

Answer 31

Frame Shift Either an addition or deletion of a abse
Base Change Reading frame is not affected
Nonsense Premature stop codon due to base change
Missence Different codon due to a base change