IMMS Flashcards
what are the rate limiting steps for glycolysis and how does it work?
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
what are the rate limiting steps of the krebbs cycle?
citrate synthase
isocitrate dehydrogenease - the main one
aphaketogluterate dehydrogenase
how does citrate synthase regulate the krebbs cycle?
is allotristically inhibited by ATP, NADH
• Succinyl CoA competitively inhibits it
Increased citrate levels also inhibit it in an equlibrium sense
how does isocitrate dehydrogenase regulate the krebbs cycle?
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)
how does alphaketogulterate dehydrogenase regulate the krebbs cycle?
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)
what happens on the three faces of teh golgi apparatus
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
what are the 5 types of cell connectors
• 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
what are the 3 fibres in teh cell and what are they each made of?
• 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
what are the water break down of a 70kg man
• 70 kg man
• 28 intracellular, 14 extra cellular - 42 litres overall
11 extra vascular 3l plasma
define:
osmosis, osmolarity, osmolality, oncotic pressure and hydrostatic pressure
• 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
defien karyotype
number and appearance of chromasomes in a cell
what are teh 5 types of DNA mutations
- 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
what is expansion of teh trinucleotide repeat and anticipation
- Expansion of the trinucleuotide repeat - triple repeat is repeated several times
- Anticipation - the repeats get bigger and there are earlier symptoms
what enzymes unwinds teh DNA from histones
topoisomerase
what unzips teh dna
DNA helicase
what prevents teh DNA from resealing again
single strand binding protien
what is a primase enzyme
• 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
which way can DNA polyemerase enzyme work in
5-3 direction
what enzyme joins teh gaps between teh ogazachi fragments
• DNA ligase joins up the gaps between the Okazaki fragments
what is teh starting codon
AUG
what is splicing
Splicing is removing the intorns nd leaving the exons in
what is teh TATA box
• 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