Notes

Question 1

Cholesterol

Answer 1

• thermal movement reduced
• bilayer thickness increased
• fewer water molecules enter the core
• stiffer, less permeable

Question 2

How many times does DNA wind around histones?

Answer 2

1.7 times

Question 3

Purines

Answer 3

Adenine, Guanine
- have 2 rings
- guanine has =O

Question 4

Pyrimidines

Answer 4

Cytosine, Thymine, Uracil
- one ring
- Cytosine -NH2
- Thymine -CH3

Question 5

Inosine

Answer 5

Two hexose rings
- binds A, C, U (not G)

Question 6

Eukaryotic replication initiation

Answer 6

• 3+5 first
• then 1
• 2 +4 are passively replicated

DnaA binds to 9mer region

Question 7

Polymerase chain reaction

Answer 7

• Denaturation (95c)
• Primer anealing (50c)
• Extension (72c)
• taq polymerase

Question 8

Eukaryotic transcription

Answer 8

Monocystronic

Question 9

Prokaryotic transcription

Answer 9

Polycistronic (has operons)

Question 10

Transcription initiation

Answer 10

• activator binds to DNA
• DNA bends so activators bind to promoter region
• enhansosome
• other TFs bind

Question 11

Post-transcriptional modifications

Answer 11

• Capping
• Splicing
• Alternate splicing
• Polyadenylation

Question 12

What catalyses peptide bond formation?
(translation)

Answer 12

23s in prokaryotes
28s in eukaryotes

Question 13

What recognises the starting sequence

Answer 13

Prokaryotes: 16s subunit recognises Shine-Delgarno

Eukaryotes: ribosome binds 5’ cap and 43s recognises Kozak sequence

Question 14

Release factors
(translation)

Answer 14

mimic tRNA
cause hydrolysis between AA and tRNA

Question 15

Amino acid modifications

Answer 15

• Phosphorylation
• N-glycosilation
• O-glycosilation
• Hydroxylation
• Carboxylation
• Methylation
• Oxidation (disulfide bond)

Question 16

equation for fraction of bound receptor (theta)

Answer 16

theta = [L]/([L]+Kd)

Question 17

Photoautotrophs

Answer 17

• light for energy
• Inorganic source of C

Question 18

Photoheterotrophs

Answer 18

• light for energy
• organic source of C

Question 19

Chemoautotroph

Answer 19

• Inorganic source for energy
• Inorganic source of C

Question 20

Chemoheterotroph

Answer 20

• Inorganic source for energy
• Inorganic source of C

Question 21

Gibbs equations

Answer 21

G=-RTlnQ
G=-nFE

Question 22

Examples of electron carriers

Answer 22

• Iron sulfate
• Cytochrome C
• Ubiquinone (coQ)
• Flavin mononucleotide

Question 23

Loose configuration (ATP synthase)

Answer 23

binds ADP,
can’t unbind

Question 24

Open configuration (ATP synthase)

Answer 24

Can bind and unbind ADP and ATP

Question 25

Anaerobic respiration

Answer 25

Pyruvate converted to lactate Pyruvate converted to acetaldehyde converted to ethanol - produces NAD+

Question 26

Intracellular lipases on adipocytes

Answer 26

- during excersize - Adrenaline, low insulin - fatty acids released into blood stream

Question 27

Lipoprotein lipases on adipocytes

Answer 27

- Late fed state - Insulin - fatty acids for cell storage

Question 28

Intracellular lipases on skeletal muscle

Answer 28

- Excersize - Adrenaline - release fatty acid for fibres

Question 29

Lipoprotein lipases for skeletal muscle

Answer 29

Fasting: use Post - excersize: store

Question 30

Phosphorylation

Answer 30

Serine, Threonine, Tyrosine

Question 31

N-glycosilation

Answer 31

Asparagine amide group of Asn forms a bond with N-acetylglucosamine

Question 32

O-glycosilation

Answer 32

Serine, Throenine

Question 33

Hydroxylation

Answer 33

Proline, Lysine Adds –OH to help with crosslinking and stabilization

Question 34

Carboxylation

Answer 34

Glutamate

Question 35

Methylation

Answer 35

Lysine, Glutamate Addition of methyl groups to nitrogen atoms