resiration and ATP Flashcards
whats the equation for atp
ADP+Pi=ATP
why do we make a lot of ATP
for various things e.g active transport metabolic processes movement etc. its unstable and only releases small amount of energy at a time
why is ATP useful
releases energy in small suitable amounts
broken down in one step
makes energy rapidly available
makes substances more reactive by phosphorylating them lowering the activation energy
can be reformed and made again
why do plants make ATP in respiration as well as photosynthesis
in the dark no ATP production in photosyn.
some tissues unable to photosyn and produce ATP
ATP can not be moved from cell to cell
plant uses more ATP than produced in photosyn
ATP for active transport
ATP for synthesis
how are enzymes in respiration affected?
by temp
describe oxidation and reduction
oxidation= lose electrons, lose H, gain O2 reduction= gain electrons, gain H, lose O2
what are the stages of respiration
glycolysis
link reaction
krebs cycle
electron transport chain
describe glycolysis
happens in cytoplasm of mitochondria Pi added to glucose to make phosphorylated glucose (6C) Glucose split into 2 triose phosphate TP oxidised, gives H to NAD to make NADH TP converted to pyruvate which releases ATP
what does the process of glycolysis make
ATP NADH pyruvate process requires ATP
describe the link reaction
happens in the matrix of the mitochondria
pyruvate is oxidised gives H to NAD
pyruvate loses CO2 becomes 2 acetyl group
2C acetate joins with co enzyme A to form acetyl coenzyme A
describe the Krebs cycle
in matrix of the mitochondria
2C acetyl coenzyme A joins with 4C molecule
NAD and FAD reduced
substrate level phosphorylation
describe the electron transport chain
on inner membrane of mitochondria
NADH and FADH release their H. this splits into protons and electrons
electrons move along carriers in the electron transport chain using redox reactions this releases energy
protein channels use this energy to actively transport H ions into intermembrane space. these then diffuse back down the conc gradient through ATP synthase into the matrix and release ATP
describe oxidative phosphorylation
protons and electrons combine with O2 to make water. O2 acts as the terminal acceptor of electrons - prevents build up of electrons
what does ETC and OP make
ATP water NAD FAD and requires ATP
what does glycolysis make
ATP NADH and pyruvate
what does link reaction make
NADH CO2 acetyl coenzyme A
what does the krebs cycle make
ATP NADH FADH CO2 4C molecule
other respiratory substances include the break down products of lipids and amino acids which enter the krebs cycle
describe anaerobic respiration
without o2. NAD is regenerated and pyruvate is removed from glycolysis
describe anaerobic respiration in plants and micro organisms
pyruvate + reduced NAD = ethanol CO2 and NAD
whats anaerobic resp in animals
pyruvate + NADH = lactate and NAD
describe effects of anaerobic resp in animals
useful when O2 in short supply but lactate is painful and less ATP is made because pyruvate is needed to make same amount of ATP
what is methylene blue used for
an artificial H acceptor in experiments e.g NAD. it becomes colourless when reduced
what must scientists do to investigate other stages of resp (other than glycolysis)
use a substance other than glucose for the respiratory substance because glucose cannot cross the mitochondrial membrane as it is usually broken down in glycolysis so cant move from cytoplasm to matrix
what are manometer tubes used for
measure rate if gas exchange. use o2 for resp and release CO2. CO2 is absorbed by something like potassium hydroxide. this lowers pressure level of liquid moves.
how do you calculate rate of resp using manometer
need to know volume of the tube, the distance moved, time taken and mass of respiring organisms
why do you leave the manometer for a while after it is set up
allow equilibrium to be reached
allow for expansion/pressure change in apparatus
allow resp rate of seeds to stabilise
use of anaerobic resp in plants and microorganisms
yeast in anaerobic conditions ferments natural carbohydrates to produce ethanol for the brewing industry
when and why anaerobic resp in animals
overcome temp shortage of O2
in times of oxygen debt - muscles use o2 faster than it can be supplied
fleeing from a predator
NADH cant be oxidised so builds up so pyruvate takes 2 H from NADH to produce lacate and NAD
