biology paper 2 mark scheme flashcards

when talking about synpases and the activation of a action potential talk about the depolrisation of the membrane

howdoes mdma work

increases serotinin

binds to post synaptic receceptors

blocks presymaptic receptirs

how can mdma cause depression

depletion of serotonin

serotonin affects mood

post synaptic mem less responsive to sero, loss of receptors on post synap mem

how does san bring change in heart rate as exercise increases

more depolarisation of san- more impulses

more freq waves of depolar from san to atria

leading to more freq contraction of atria / stim of avn

x chromosone carrie genes not y

how does systic fibrosis affect rate of oxygem uptake in ;ungs

• thick mucus

• restrict airflow in bronchioles (DONT SAY AIRWAYS)

• mucus cant be moved by cilia

how do two alpha glucose form

• condensation

• glycosidc bonds form

• water realsed

• oh group on both molecules involved

advantage of storing glycogen

• glycogen is a polymer of glucose

• glucose used in repiration to provide energy / atp

• branched so can be hydrolysed / broken down quickly into glucose

what ahppens to calcium ions after no ap n muscle contraction

taken up by sarcoplasmic reticulum by active transport

why cant omethingt produce hapolid nucleuys

• odd number of chromsomes

• no homologous pairs

• no meisosis

why are phospohlipds arranged in two layers

need 2 layers as solution on eiether side of the membrane

• hydophilic and phobic

how does a PET scan work

• detects gamma rays

• 3d image

• radioactive tracers

when talking about heart rate talk about cardovascular centre as well as medulla oblongata

how can too much exercise be harmful to body

increase wear and tear of joints ‘

can cause damage to them

pain

weaken immune system/ suppressed

more pathogens can enter and cause infection

compare and contrast actin and collagen

• collagen = 3 chains , actin = 1 chain

• both made up of amino acid joined by peptide bonds

• both ave more then one polypeptide chain

when testing for hypothesis

do a stat test

compare calc to crit value

accept or reject hypothesis

atp supplies energy

in the elctron trasnport chain of oxidative phosphorylation electrons are transferred in redox reactions

when talking about say that they are genetically identical not just that they just share 100 percent dna

animals , plants and bacteria can all be genetically modified

descfribe role of enzymes in the synthesis of personalised proteins in gmos

• dna helicase break h bonds

• rna polymerase makes mra/trasncribed

• nucleotides joined by phosphodiester bonds

• amino acids join together - peptide bonds

example of a grwoth response of a planyt affceted by phytochrome

germinations

how does the strucutre of phospholipase allow it to hydrolyse phospholipids

• hydrophil and phobic

• actve site comp to phospholipid

• struc of enxymes detrermined by seq of amino acids

• tiertary provides active site

• break ester bond

cold temps mean vasocontriction so shunt vessels contrict

in warm temps its vasodilation so shunt vessels dilate

is heat loss when sweating due to dipole nature of water

yes

water has uneven charge - dipole

forms h bonds with other water moelcules

lots of e needed to break bonds

evaporation occurs

muscle fibre has many mitochondria

why does redcued nad need tp be oxidised in a mitochondriaon

so hydogen can be delieved in electron trasnport chaon

allows chemiosmosis

regenerate nad

when discussing two things that are closely related say they have more recently evolved from a common ancestor

a polysaccaride is a chain of glucose

what joins dna together

dna ligase

structural differences between slow and fast twitch fibres

• fast = no mitochondira

• slow = many mitochondria

• fast= no capillaries

• slow= many capilalries

why was data collected from another group

could be as a control

how can crossing over of chromatids lead to genetic variation

• between non sister chromatids

• of homologous pairs

• swappiung of alles

• same genes but diff alleles

sugar in both euk and pro dna is deoxyribose

large wound from open surgery = more access for pathogens than key hole surgery which is a small wound

ethical issues of preimplantation genertic diagnosis

• not 100 accurate

• designer babies

• embryo could be destieyed -right ti life

how does cysisic fibrosis affcet digestions

• niormal things i know

• blocks flow of bile

whats semi conservative dna replication

• doubling of dna

• acts as a template

• one new and one original strand

role of atp in trasnmission of impulses

• atp needed for sod/pot pumps

• move against conc grad

• maintain pd

why are lipids needed in schwann cells

• elecrtcal insulator

• only depolarisation at nodes of ranvier

• allows salstaory conduction

• phosphlipid bilayer

• movement through channels

why may a regio n of the brain appear light in an image by fmri scan

• more activity

• increase flow

• fmri signals are not absorbed by o2 blood

when writing null hyp say no diff between ….

what part of spern cintains enzymes that phosphorylate glucose in respiration

• cytolpasm

describe interaction of muscles in the eye that cause dilation of pupils

• antagonistic interaction of muscles

• in the iris

• radial contract ,circular relax

how does cartilage prevent wear and tear

its a cushioning

acts as a shock absorber

advantgade of fmr and pet compared to mri

live image

activity vs structure

why do cells convert pyruvate to lactate

• glycolysis can contrinue

• atp can be made

• anaerobic respiration

• produce nad

compare saturated and unsaturated fatty acod

both have hydricarbon chain

both have c-c bonds

both have carboxylic acid group

unsaturated has a c=c

saturated =straight chain

unsaturated = bent/ kink in chain

when talking about blood clots say lumen in capillarirs in blocked not arteries

oxygenated blood aborsts less radio waves in fmri

how to talk about continous flow respirometer

• use soda lime -aborbs co2

• measure vol of air enter and leaving chamber

• decrease vol represents o2 uptake

• control temp

role of dendrites

• from synapses with other neurones

• recvieve info from other neurones

• involved in summation

• take action potential to cell bond

what happens to lysosomes when their content has been digested

content eleased from cell

exocytosis