Central Dogma & Enzymes

Question 1

DNA → mRNA

Answer 1

Transcription

Question 2

mRNA → Proteins/amino acids

Answer 2

Translation

Question 3

What is the directionality of mRNA?

Answer 3

5’ Methyl cap → 3’ Poly A tail

Question 4

Steps in Transcription:

Answer 4

1) Initiation
RNA polymerase attaches to promoter & TFIID shoots to start

2) Elongation
RNA polymerase moves along strand exposing 10-20 bases (THERE ARE MULTIPLE SITES)

3) Termination
2 types
Rho dependant
Rho-Indepenadant

4)Post transcriptional modifications
5’cap
3’Poly A tail
Splicing
Alternative splicing

Question 5

Rho-dependant termination

Answer 5

P PROTEIN WEDGES

• binds to mRNA transcript
• moves reverse and eventually catches up to RNAPol to them stop it and kick itout

Question 6

p protein

Answer 6

wedges in rho dependant termination

Question 7

Rho- Indepenadant

Answer 7

HAIRPIN

• RNA transcript fold back over self physically disrupting RNA path
• rich in G and C but end stretch bunch of U

Question 8

What are the post transcriptional modifications

Answer 8

pre mRNA → Mature mRNA

Add 5’ cap (methyl group)
Add 3’ poly A tail
Splice out introns
Alternative splice, remove certain exons to make proteins

Question 9

Alternative splicing

Answer 9

remove certain exons to make proteins isoforms

Question 10

Steps in Translation:

Answer 10

1) Inititation
- Small ribosomal subunit attaches to Methyl cap and slides to the start codon AUG
- tRNA with the anticodon for AUG binds to P site and brings in corresponding amino acids methionine

2) Elongation
- Another tRNA joins at the A site to then start the movement
- Methionine from previous amino acid attaches to this one and begins movement
- Shift and tRNA leaves after giving away it aminoacids

3) Termination
- When mRNA reaches stop codon tRNAs recognize it and bring in a release factor

Question 11

Peptidyl transferase

Answer 11

Enzyme that catalyses the attachement/peptide bond making of amino acids

Question 12

Post translational protein modifications

Answer 12

Covalent (EX. phosphorylation)
Cleavage/cutting

Question 13

Histone

Answer 13

Protein that the DNA is wrapped around

Question 14

Nucleosome

Answer 14

DNA wrapped around the histone

Question 15

Purines

Answer 15

PURE AS GOLD(AG)

Adenine
Guanine

Question 16

Pyrimidines

Answer 16

Thymine
Cytosine
Uracil

Question 17

Nucleotide polymer (DNA backbone)

Answer 17

• Back bone charge is negative
• always labeled 5’ →3’
• Made of: sugar, phosphate and base

Question 18

DNA polymerase |||

Answer 18

• Synthesizes new strand
• On the leading strand

Question 19

DNA polymerase |

Answer 19

• removes primers on lagging strand and fills in the gaps
• proof reads
• removes primers and correlates mismatched pairs

Question 20

how many H bonds do G-C have?

Answer 20

3

Question 21

how many H bonds do A-T have?

Answer 21

2

Question 22

DNA denaturing when…

Answer 22

• pH less than 3 OR greater than 9
• Heat to greater than 60 degrees (melting temp when half helical shape lost)

Question 23

DNA packaging. how are the proteins charged?

Answer 23

Basic proteins like Arg & Lys are positively charged and are. made to interact with negatively charged DNA

Question 24

Is DNA negatively or positively charged?

Answer 24

NEGATIVELY

Question 25

Cofactors

Answer 25

INORGANIC
EX. Zn 2+, Fe 2+

Question 26

Coenzymes

Answer 26

ORGANIC
EX. Vitamins

Question 27

Holoenzyme

Answer 27

Active enzyme complex
enzyme bound to cofactor or coenzyme

Question 28

Apoenzyme

Answer 28

Enzyme alone is inactive

Question 29

How do substrates bond to the acive site?
2 methods

Answer 29

NON COLVALENT interactions
Lock in key method
Induced fit model

Question 30

Lock in key method

Answer 30

Perfect fit

Question 31

Induced fit model

Answer 31

Overtime gradually shapes into fit better

Question 32

Enzyme related diseases: TISSUE DAMAGE

Answer 32

elevated enzyme presence in plasma (out of cells)

Question 33

Enzyme related diseases: LIVER DISEASE

Answer 33

ALT= liver enzyme
if found in blood liver is damaged

Question 34

Enzyme related diseases: HEART DISEASE

Answer 34

Cardiac enzymes could be found in plasma. that way can find out if heart is damaged

Question 35

Exergonic

Answer 35

less energy left as opposed to when we started

Question 36

Endergonic

Answer 36

more energy left as opposed to when we started

Question 37

what does it mean when DELTA G is 0?

Answer 37

Equilibrium

Question 38

Michaelis-Menton Model

Answer 38

Model to described catylized enzyme reactions (NOT allosteric enzymes)

Question 39

What shape is the Michaelis-Menton Model?

Answer 39

Rectangular porabola

Question 40

Km=

Answer 40

A suubstrate [ ] that tells us how much substrate is required to get to half Vmax.

Question 41

HIGH Km

Answer 41

Low affinity for substrate

Question 42

LOW Km

Answer 42

High affinity for substrate

Question 43

Lineweaver Burke EQ

Answer 43

Double reciprocal of Michaelis-Menton EQ (both sides put 1 over)

Question 44

Environmental factors affecting enzyme activity

Answer 44

pH
EX. Stomach enzymes work better in stomach acid pH

Temperature
EX. enzymes work faster at high temp but at a certain point denature because too hot

Question 45

Cold blooded animals in the cold

Answer 45

move slow because enzymes move slow

Question 46

Hydrothermal Vents have Thermopiles aquaticus

Answer 46

animals that love the heat so their enzymes work better in hot

Question 47

Siamese cats

Answer 47

Pigmentation enzyme is sensitive to heat and denature sat cats body temp

So only the cold parts of the cat are pigmented like nose and paws

Question 48

Alosteric enzymes

Answer 48

Sigmoidal curve
have the little indent

Question 49

Alosteric regulators (name and 2 types)

Answer 49

Effectors:
Homotropic
Heteroptropic

Question 50

Homotropic effectors

Answer 50

Substrate changes shape and goes into alosteric site to ACTIVATE

Question 51

Heterotropic effectors

Answer 51

Foreign molecule comes into allosteric site and either INHBITS OR ACTIVATES

Question 52

Covalent modification of an enzyme (EX and difference between allosteric regulation)

Answer 52

EX. Phosphorelation
Takes longer because need other reactions involved

Question 53

Positive regulator:
what it does?
whch way shift?

Answer 53

helps make more
Shift left

Question 54

Negative regulator:
what it does?
whch way shift?

Answer 54

stops production
Shift right