IMMS Flashcards

1
Q

what are the rate limiting steps for glycolysis and how does it work?

A

PFK (phosphofructise kinase)
is allotrisitacally inhibited by ATP and citrate.
• This means that when tere are high levels og this glycolysis slows down so that not too much energy is produced
• AMP (used up ATP) acts as a stimulator for it
• Fructose 2 6 biphosphate (made as an isomer of 1,6 biphospahte) is an activattor of PFK too as it acts as an intermediate signaler for insulin and glucagon to increase or decrease enegry metabolism

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2
Q

what are the rate limiting steps of the krebbs cycle?

A

citrate synthase
isocitrate dehydrogenease - the main one
aphaketogluterate dehydrogenase

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3
Q

how does citrate synthase regulate the krebbs cycle?

A

is allotristically inhibited by ATP, NADH
• Succinyl CoA competitively inhibits it
Increased citrate levels also inhibit it in an equlibrium sense

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4
Q

how does isocitrate dehydrogenase regulate the krebbs cycle?

A

acts as a speeder upper of the krebbs cycle by getting rid of more citrate which is an inhibitor for citrate synthase (krebs) and PFK (glycolysis)

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5
Q

how does alphaketogulterate dehydrogenase regulate the krebbs cycle?

A

inhibited by its products NADH and Succinyl CoA

• It is activated by Ca2+ (which moves into cells for muscle contraction when more ATP will be needed)

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6
Q

what happens on the three faces of teh golgi apparatus

A

The cis golgi is facing the nucleus and protien phosphorylation happens here
• The medial golgi adds sugards and forms oligosaccorides by adding sugars to lipids and peptides
The trans golgi does the prteolysis of peptides into acitve fomrs and sorts out molecues into vesicles

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7
Q

what are the 5 types of cell connectors

A

• tight junctions are waterprood and prevent leakage
• Adherens - join togethre actin bundles to other cells
• Desmasomes - jointeh intermediate fibres ot one another
• Gap junctions - allow passage of ions
Hemi desmosomes - join intermediate fibres in a cell to the basement membrane

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8
Q

what are the 3 fibres in teh cell and what are they each made of?

A

• Microtubules - arise from the centromere and are neede for mitosis. They are 25nm long and its tubulin
• Intermediate fobres - 10nmm 6 protine types and theyre anchoured ot the transmembrane protiens which are spread through the tissue
Microfilaments - -5 nm, actin

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9
Q

what are the water break down of a 70kg man

A

• 70 kg man
• 28 intracellular, 14 extra cellular - 42 litres overall
11 extra vascular 3l plasma

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10
Q

define:

osmosis, osmolarity, osmolality, oncotic pressure and hydrostatic pressure

A

• Osmosis - net movemnt of water from an area of high to lw concentration
• Osmolarity - concentraction of solutes in plasma per litre of solution
• Osmolality: Concentration of solutes per kg of solution
• Onoctic pressure, the pressure exerted b proteins that draws water in - notibily albumin
Hydrostatic pressure is the pressure difference between capillaries and interstitial fluid

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11
Q

defien karyotype

A

number and appearance of chromasomes in a cell

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12
Q

what are teh 5 types of DNA mutations

A
  • Duplication - sections repeating
    • Deletions - its read out of frame ot a codon id lost and one aa is missing
    • Non sense - premature cstop codon is produced so the protine is dysfunctional
    • Missense - change in a singe AA, can have no effcet or can be detramental
    • Spice site mutation - removal of an intoron
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13
Q

what is expansion of teh trinucleotide repeat and anticipation

A
  • Expansion of the trinucleuotide repeat - triple repeat is repeated several times
    • Anticipation - the repeats get bigger and there are earlier symptoms
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14
Q

what enzymes unwinds teh DNA from histones

A

topoisomerase

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15
Q

what unzips teh dna

A

DNA helicase

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16
Q

what prevents teh DNA from resealing again

A

single strand binding protien

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17
Q

what is a primase enzyme

A

• A primase enzyme makes a short section primer (a short sequence of RNA) that polymerase can start to work from as it cant start off by itself

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18
Q

which way can DNA polyemerase enzyme work in

A

5-3 direction

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19
Q

what enzyme joins teh gaps between teh ogazachi fragments

A

• DNA ligase joins up the gaps between the Okazaki fragments

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20
Q

what is teh starting codon

A

AUG

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21
Q

what is splicing

A

Splicing is removing the intorns nd leaving the exons in

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22
Q

what is teh TATA box

A

• TATA box is a promoter sequane and is a promoter gene and the beinding sight of transcription
It marks te start of a gene roughly

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23
Q

what happens in each stage of mitosis

A

• Prophase - nucleur envelop breaks down, chromain condenses into chromasones
• Prometaphase, spindle fibres attatch at the centromere
• Metaphase, line up on the metaphase plate,
• Anaphase, pulled apart to the poles of the celll
Telophase, nucleure membrane begins to reform

24
Q

what is teh last stage of mitosis

A

cytokinesis!!!

25
Q

what tow steps causes genetic variation in miosis

A

Crossing over in prophase 1 and independan assortment in metaphase 1 cuases genetic variation

26
Q

what is mosacism and gonadal mosacism

A

• Mosacism - error in cell division and the sam ecells have a different genetic makeup
Gonodal mosacism - sperm have differnet dna

27
Q

how many ATP will a glucose make and where

A

• 1 glucose will make 28 atp, 2 from krebbs, 2 for glycolysis and 34 from oxidative ohosphorilation

28
Q

what are the fidderent compleces of teh electorn transport chain

A

• The electon transport chain has 2 clomplexes
• Complex 1 - removes elecrtron from nadh
• Complex 2 removes electrons from nadh
Complex 3, 4 dontes the enzymes to cytokrimes containing iron

29
Q

what doe steh citrace shuttle do? and what are its steps?

A

Synthesis of faty acids happens in geh cytoso of the mitochondira and so it needs to moved across the membrane via the citrate shuttle
• Oxpcetate binds with acetyl co to to from citrate, this can tehn cross te membrane
• Citrate ligase then converts it back into oxoaceteate and acetyl co a
• This can be broken down into pyruvae ad acetyl co a
• The pyrivat ethen moves bac into the mitochndira and enters the krebbs cycle

30
Q

what does the carnatine shuttle do and how does it work?

A

• The cartanine shuttle moves the fatty acids across the mitochondrial membrane
• The aceyl co a is converted to caetly cartanine and the co a os recycled inot anoher biochemical reaction
• This can tehn cross te membrane
• On the inside it is converted back niyo acyl co and and the cartanine can move out again
Once inside it can go though beta oxidation

31
Q

what is eh differnece between acyl co a and acetyl co a

A

• Actyl coA is what goes into the krebbs cycle

Aceyl co a is derived from fatty acidsa nd is turned into acetyl coA, NADH and FADH though beat oxidation

32
Q

what happens in te process of fatty acid oxidation

A

• Aceyl co a is derived from fatty acidsa nd is turned into acetyl coA, NADH and FADH though beat oxidation
2 carbonds are removed at a time and then the NADH and FAD undergo oxidative ohosphorilation and ATP is produced

33
Q

what enzyme does teh liver lack meanign that it cant undergo ketone metabolsim

A

The liver lacks the enzyme succinyl co a accetoaccetyl Co a transferase

34
Q

what is teh most potent oxygen radical

A

OH-

35
Q

what is the fenton reaction

A

Fe2+ + H2O2 > Fe3+ + OH- + OH•

36
Q

what is teh harber wiess reactions

A

O2• + H+ + H2O2 > O2 +OH• + H2O

37
Q

what enxymes is used to make OH radical in teh respiritory burst

A

• NADPH oxidase is the enzyme used in the respiritory burst to make the superoxide molecules
Catalse breaes down h2o2 in order to prevent lots of free radicasl

38
Q

what is teh henderson hasslebac equation

A

pH= pK + log(a-/HA)

39
Q

what is teh henderson hassleback equatin specifically for teh carbonic acid

A

pH = 6.1 + log10 (25mM / (0.03 x 40 mmHg))

0.03 is te constat for CO2

40
Q

what is teh anion gap

A

The anion gap s the differnece in concntraions of cations and anions

41
Q

what is teh normal rage for teh anion gap, and what do narrower or wider gaps indicate

A
  • The normal rnage is 3-11meq/ml

* Widr gas could indicate acidocis, and narrow gaps could inductae renal acidicos

42
Q

name 4 buffers in the body

A

• Bicarbonate is the buffer of the body
• Albumin is also used as a buffer and can absorb the spare H+ ions
• The protien matric of bone can buffer greater amounts of H + ions and act as a large buffer
• Heamoglobin is aos a big buffer syste
Deoxygenated heamoglobn has eh strongest affinity for CO” and H+ which leads to it being ore effective as a buffer

43
Q

causes of metabolic acidosis

A

• Metabolic acidocis - caused by retention of acids, kindey faliure, ketoacidocis in diabetics, loss of bicarbonate, hyponatremia

44
Q

causes of metabolci alkalosis

A

• In metabolic alkalocis - vomiting or diareah, too much H+ is lost, alkali ingestion, hyperkalema

45
Q

what are the differnt types of collagen

A
1 - skin and bone 
2 - cartilage 
3 - liver, bone marrow and spleen (reticulin) 
4 - basement membrane
5 - placenta
46
Q

Vitamin A

What its found in, daily allowance, function

A

cereals, eggm oil, dairy, its absorbed as beta carotene
visio, growth, reproduction clle membranes

900ug

47
Q

Vitamin D

What its found in, daily allowance, function

A

UVB, diet and supplement,
increased calcium absorbtion, bones, renal excretion,
5-10ug

48
Q

vitamin e

What its found in, daily allowance, function

A

Oils, carrots, leafy greens#
antioxident
3-4ug

49
Q

vitamin k

What its found in, daily allowance, function

A

leafy green s, K1 from food, K2 from intestinal bacteria,
blood clotting
120ug

50
Q

vitamin C

What its found in, daily allowance, function

A

fresh fruits and veg
collagen synthesis, antioxident, iron absorption
40mg

51
Q

Vitamin B9

What its found in, daily allowance, function

A

coenzyme in methylation, DNA synthesis,
THIS IS THE SAME AS FOLIC ACID!!!
400ug

52
Q

vitamin B12

What its found in, daily allowance, function

A

from food relased by intrinsic factor

stored in teh liver and important for blood metabolism, pernicious anemia is caused by its deficancy

53
Q

define allele

A

a varitation fo a gene at a specific loci

54
Q

what are polyorphisms

A

frequent hereditry variations at a locus, that ae you more or less liekly o be suseptabel to a disease

55
Q

define penetrance

A

proportion of people with genotrype who show teh expected pheontype

56
Q

define heritibility

A

Heritability is a measure of how well differences in people’s genes account for differences in their traits.