Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Uni year 1 > FLS > Flashcards

FLS Flashcards

1
Q

Which steps of glycolysis are not reversible?

A
  1. glucose –> glucose-6-phosphate by hexokinase
  2. fructose-6-phosphate –> fructose-1,6-bisphosphate by phosphofructose kinase
  3. phosphoenol pyruvate –> pyruvate by pyruvate kinase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How can step 10 of glycolysis be reversed?

A

pyruvate carboxylase converts pyruvate to oxaloacetate

phosphoenol pyruvate carboxykinase converts oxaloacetate to phosphoenol pyruvate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How can step 3 of glycolysis be reversed?

A

fructose-1.6-bisphosphatase converts fructose-1,6-bisphosphate to fructose-6-phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Howcan step 1 of glycolysis be reversed?

A

glucose-6-phosphatase can be used to convert glucose-6-phosphate to glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the corrie cycle?

A

Glucose is sent from stores in the liver to exercising muscles where it is used and converted to lactate. Lactate is then taken to the liver where it can be converted back to glucose by gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why is the corrie cycle important?

A

prevents lactic acidosis in the muscles

regenerates NAD+ to be used in glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does the pyruvate dehydrogenase complex do?

A

converts pyruvate into acetyl CoA by pyruvate decarboxylation so that it can be used in the Krebs cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the PDH complex formed of?

A

24 transacetylases in trimers
24 pyruvate dehydrogenase in dimers
12 dihydrolipoyl dehydrogenases in dimers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some targets for antibacterial action?

A
  • Cell wall synthesis inhibitors - enzymes that form peptidoglycan cell wall
  • cell membrane
  • nucleic acid synthesis
  • protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give 6 examples of antibiotics in clinical use

A 
glycopeptides
beta-lactams
aminoglycosides
tetracyclines
chloramphenicol
macrolides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How to determine for susceptibility of an antibiotic?

A

Disc susceptibility - place antibiotic disc on agar plate and maeasure diameter of cleared zone
E-test - concentration range is high to low, where the bacteria crossses is the minimum inhibitory concentration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the minimum inhibitory concentration of an antibiotic?

A

The dilution of a drug that

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why are some bacteria particularly hard to kill with antibiotics?

A

Some have pores on the outside that act as molecular sieve

Some vacuums anything out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the breakpoint concentration of an antibiotic?

A

The concentration at which it will be effective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are phase variable genes and what are some mechanisms?

A

Able to turn genes on or off which occurs as a result of ‘programmed’ mutations

  • genomic rearrangement - if promoter changed then transcription won’t occur
  • Strand slippage - transcriptional or translational, results in nucleotide repeats
  • Methylation - methyl group added to DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

By what mechanisms can DNA be exchanged in bacteria?

A

Conjugation
Transduction
Transformation

17
Q

How can DNA be exchanged in bacteria by conjugation?

A

Physical connection formed between 2 cells

Plasmid passed from one cell to another

18
Q

How can DNA be transferred by transponsons?

A

Transponsons are pieces of DNA that are moved from one location to another
copy and paste method: sequence copied to RNA the to DNA (by reverse transcriptase) then inserted elsewhere
cut and paste method: transponsons cut out of DNA and inserted elsewhere

19
Q

How can DNA be transferred by transduction?

A
  • bacteria infected by virus (phage)
  • phage injects own DNA into bacterial chromosome
  • phage replicates inside cell
  • bacteria lyses releasing particles
  • infects new cell
20
Q

How can DNA be transferred by transformation?

A

uptake of naked DNA from environment

21
Q

What are the 4 phospholipids that make up the plasma membrane?

A 
Phosphoglycerides:
phosphatidylserine
phosphatidylaethanolamine
phosphatidylcholine
Sphingoipids:
sphingomyelin
22
Q

What is the shape of a free fatty acid and what shape would a group form in water?

A

Cone

Forms a micelle in water

23
Q

What is the shape of a phospholipid and what shape does a group form in water?

A

cylindrical
phospholipid bilayer
A phospholipid bilayer is energetically unstable because the sides are exposed so they would tend to fold into a ball to form a sealed compartment`

24
Q

Where are phospholipids synthesised?

A

SER - in the outer cystolic leaflet

25
Q

Synthesis of phosphatidylcholine

A

Fatty acid is synthesised in the cytosol and transported to the ER by a fatty acid binding protein
Fatty acid embeds in membrane
Phosphate, glycerol and choline added

26
Q

How is the plasma membrane synthesised?

A

Phosholipids synthesised on outer cytosolic leaflet of ER membrane
ER enzyme scramblase synthesises ‘flip-flop’ to evenly distribute the phospholipids between the outer and inner leaflets of the ER membrane
Part of the membrane buds out to form a vesicle
Newly synthesised membrane transported to plasma membrane
Inside of ER membrane becomes outside of plasma membrane

27
Q

What are peripheral proteins?

A

Proteins that are associated with proteins embedded in the membrane

28
Q

What is the glycerol phosphate shuttle?

A

NADH from glycolysis can’t cross the inner mitochondrial membrane
FADH2 is produced in the mitochondria because it is a product of the Krebs cycle
Electrons from NADH are passed directly to FAD

NADH from Krebs is still oxidised by protein complex I

29
Q

Why is mitochondria in brown fat different to normal?

A

Has an uncoupled protein (dinitrophenol) which allow H+ to move through the inner mitochondrial membrane. This means that some energy produced from the electron transport chain will be converted into heat instead of ATP.

30
Q

What does vitamine B1 deficiency cause and why?

A

Muscle weakness because pyruvate can’t be converted to acetyl CoA
No Krebs
No ATP

31
Q

How does a protein get into the ER?

A
  • A protein has a signal peptide at the N-terminal end
  • the signal peptide directs the protein from the ribosome to a translocator on the ER membrane
  • The peptide is threaded through the membrane
  • The signal peptide is cleaved and protein released into ER
32
Q

How to integrate a single pass transmembrane protein

A
  • The protein will need to have a signal peptide at the N-terminal and a stop transfer sequence
  • The signal peptide directs the polypeptide from the ribosome to the translocator in the membrane
  • The protein is threaded through until it reaches the stop-transfer sequence where translocation is stopped
  • the signal peptide is then cleaved
33
Q

How to integrate a double pass trans membrane protein

A

Protein must have an internal signal peptide and a stop-transfer sequence
The signal peptide is not cleaved at the end

34
Q

What is the glycocalyx?

A

A carbohydrate rich layer surrounding cells composed of glycoproteins and glycolipids

35
Q

K+ channel

A
  • pore is negatively charged by amino acids
  • hydrated potassium ions can get as far as the vestibule and then they are too big
  • energy is used to dehydrate the K+ but then the energy is regained when K+ forms binds with carbonyl oxygens lining the selectivity filter
  • This means it is energetically favourable whereas other ions wouldn’t be able to regain the energy so it wouldnt be energetically favourable

Uni year 1 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions