Biological Molecules and Enzymes

Question 1

Uncompetitive Lineweaver-Burke

Answer 1

Parallel

Question 2

Competitive L-B

Answer 2

• Same Vmax

- Increased Km

Question 3

Noncompetitive L-B

Answer 3

• Same Km

- Decreases Vmax

Question 4

Mixed L-B

Answer 4

Alters both Km and Vmax

Question 5

Uncompetitive inhibitor

Answer 5

• Binds E-S complex to decrease Vmax

- Decreases both Km and Vmax

Question 6

Why do proteins denature in heat?

Answer 6

Non-covalent bonds are disrupted

• Ex. Hydrogen bonds (much weaker than covalent bonds, but strongest intramolecular bond)

Question 7

Noncompetitive inhibitor

Answer 7

• Binds to enzyme/ES complex allosterically
• Does not change Km
• Vmax decreases

Question 8

Competitive inhibitor

Answer 8

• Binds to active site

- Km increases and Vmax stays the same

Question 9

Mixed inhibitor

Answer 9

• Km can increase or decrease (based on whether I binds E or ES complex)
• Vmax decreases

Question 10

Bonds b/w carbohydrates are formed by what process?

Answer 10

Dehydration

Question 11

Peptide bonds b/w amino acids are formed by what process?

Answer 11

Dehydration

Question 12

Lipids are _____ dense than proteins

Answer 12

Less dense

Question 13

What type of cholesterol has the highest ratio of lipids to proteins?

Answer 13

VLDL

• Lowest density = must be highest ratio of low-density lipids to high-density proteins

Question 14

DNA is read in what direction?

Answer 14

5’ to 3’

Question 15

DNA is transcribed in what direction?

Answer 15

3’ to 5’

T = Three = Transcribed by RNA Pol

Question 16

How many possible codons are there?

Answer 16

4^3 = 64

• 4 nucleotides, 3 slots

Question 17

Mixed inhibitor

Answer 17

• Decreases Vmax
• Can increase or decrease Km
• Binds E or E-S

Question 18

Euchromatin

Answer 18

Loosely packed, transcriptionally active DNA

Question 19

Heterochromatin

Answer 19

Densely packed, transcriptionally inactive DNA

• H = hibernating

Question 20

DNA methylation

Answer 20

Adds methyl group to DNA => gene silencing

Question 21

Histones are affected by ________

Answer 21

Acetylation and deacetylation

Question 22

Acetylation

Answer 22

Uncoil DNA so that it can be accessed to express genes

Question 23

Deacetylation

Answer 23

Coil DNA tighter to prevent genes from being expressed

Question 24

Nucleosomes

Answer 24

Repeating units in chromatin

• DNA wraps around histone core

Question 25

Histones

Answer 25

Core of proteins that DNA wraps around

Question 26

Chromosome

Answer 26

Well-defined chain of DNA made before replication

Question 27

Chromatin

Answer 27

Mess of DNA jumbled together

Question 28

Chromatid

Answer 28

Each individual copy of a replicated chromosome - Two sister chromatids = one chromosome (connected by a centromere) - Once separated => two separate chromosomes

Question 29

Centromere

Answer 29

Connects sister chromatids into chromosome

Question 30

In what direction is translation?

Answer 30

Amino acids are added to 3' end (C terminus)

Question 31

Alternative splicing

Answer 31

Production of different mature mRNA from same initial transcript => different proteins from same sequence

Question 32

Centrosome

Answer 32

Located on sides of cell Release microtubules to attach to chromosomes during metaphase S = Sides of cell = centroSome

Question 33

Kinetochores

Answer 33

Location on chromosomes where microtubules from centrosomes attach

Question 34

Prophase I

Answer 34

- Nuclear envelope disappears - Chromosomes become dense - Crossing over

Question 35

Metaphase I

Answer 35

- Centrosomes send out microtubules to attach to kinetochores of chromosomes

Question 36

Anaphase I

Answer 36

Homologous pairs get pulled apart - Sister chromatids stay together (different from mitosis and meiosis II)

Question 37

Telophase I

Answer 37

- Cytokinesis begins - Nuclear membranes reform - Chromosomes unravel

Question 38

Result of meiosis I

Answer 38

Two haploid cells have been formed from one diploid cell (change in ploidy) - 46 chromosomes/cell => 23 chromosomes/cell

Question 39

Smooth ER = ______ ______

Answer 39

Lipid produciton