5- Energy Transfers in and between organisms Flashcards
Why is oxygen needed for the production of ATP on the Cristae of the mitochondrion.
(3)
ATP is formed as electrons pass along ETC.
Oxygen accepts electrons from ETC
Forms H20/ oxidises reduced NAD
Without ATP and reduced NADP why is there less uptake of CO2?
Less GP is converted into TP
Less TP is converted to RuBP
Name the substance which combines with CO2 in a chloroplast?
RuBP
Why does inhibiting the electron transfer decrease uptake of CO2?
(2)
It decreases ATP producuction
So less reduced NADP is produced
Where is NAD reduced?
Glycolysis
Krebs cycle
Where is NADP reduced?
Light dependent reaction
Where is ATP produced?
Glycolysis
Krebs cycle
Light dependent reaction
Where is ATP required?
Glycolysis
In the production of ATP from ADP and phosphate, what substrate is added?
Pyruvate
In anaerobic respiration what is the net yield of ATP per glucose molecule?
2
Give two advantages of ATP as an energy storage molecule ?
Stores / releases small amount of energy
Immediate source of energy
Describe how NAD is regenerated in anaerobic respiration in yeast cells?
Formed when reduced NAD is used to reduce pyruvate.
Where in the cell is rubisco found?
Stroma
If concentration of oxygen increases, what happens to rate of absorption of CO2?
As oxygen concentration increases less rubisco binds with CO2
Competition between oxygen and carbon dioxide for rubisco
During the LIR reaction of photosynthesis, carbon dioxide is converted to organic substances.
Describe how
(6)
CO2 combines with RuBP
Produces two GP molecules (this is catalysed by rubisco enzyme)
GP reduced to TP
Using reduced NADP
Using energy from ATP
Word equation for photsynthesis?
Carbon dioxide + water + (light) = glucose and oxygen
Where is the site of photosynthesis?
Chloroplasts
Factors which affect rate of photosynthesis?
Carbon dioxide concentration
Light intensity
Temperature
How are chloroplasts adapted for photosynthesis? (4)
- stacks of thylakoid membrane called grana provide large SA
- network of proteins hold the chlorophyll to absorb the max light.
-ATP synthase channels allow ATP synthesis and proton gradient.
-contain DNA and ribosomes allowing for shnthesis of proteins.
Light dependent reaction (5)
( Photosynthesis stage 1 )
-photons of light hit chlorophyll causing e to become excited (PHOTOIONISATION)
-photolysis of water ( 1 molecule of H2O = 1 O2 + 4H+ + 4e )
- 4 electrons replace lost from chlorophyll and H+ move into stroma
- e moves down ETC provides energy for 4H+ to thylakoid.
- e moves down chain to PSI , e combines with H+ to form Hydrogen
- Used to reduce NADP into NADPH ( reduced NADP)
- Proton gradient with high conc in thylakoid and low conc in stroma move by diffusion.
- Aids photophosphorylation ( enzyme ATP synthase breaks ATP into ADP and phosphate
Light independent reaction ( Calvin cycle )
(Photosynthesis Stage 2 )
- CO2 fixation
- Diffused through stomata, fixed with RuBP ( carboxylation )
- rubisco enzyme
- 6 carbon formed but turns into 2 G3P - REDUCTION
- 2 G3P contains -COOH group (acid)
- Reduced NADP reduces 2 G3P (ATP provides energy) produces 2TP - REGENERATION OF RuBP
- 5TP regenerate 3RuBP - 2TP form hexose sugar and then glucose
6 turns produce 1 molecule of glucose
Aerobic respiration definition
Splitting of a respiratory substrate to release CO2 as waste product.
Releases energy
Anaerobic respiration definition
Absence of oxygen
Produces lactic acid
Where does glycolysis take place
Cytoplasm
What does glycolysis produce ?
2 molecules of pyruvate
2 ATP
2 NADH
What happens to glucose in glycolysis ?
It is phosphorylated
What happens to pyruvate in anaerobic respiration ?
Converted to lactate using NADH
What does one molecule of glucose produce in glycolysis?
2 ATP ( net gain )
2 reduced NAP ( NADPH)
2 pyruvate
What happens to 2 pyruvate molecules from glycolysis ?
Actively transported to mitochondria for link reaction
What enzyme is involved in link reaction ?
Decarboxylase
What does Decarboxylase enzyme do in link reaction ?
Removes CO2 with H removed to reduce NAD
What are the products of link reaction ?
Acetyl coenzyme A
How is acetyl coenzyme A formed ?
Acetate combines with coenzyme A
How many acetyl coenzyme A produced per molecule of glucose ?
2
Where does the krebs cycle take place ?
Matrix of mitochondria
What is given to 4 carbon to produce 6 carbon molecule ?
2 carbon acetate from acetyl coenzyme A
How many time does the krebs cycle turn per molecule of glucose ?
2
In krebs cycle , per glucose molecule , what are the products ?
2 ATP
6 NADH
2 FADH
4 CO2
Process of oxidative phosphorylation ? (4)
- Reduced NAD ( NADH) from krebs releases hydrogen , protons and electrons
Reduced FAD ( FADH) releases hydrogen , protons and electrons
Protons move to mitochondrial matrix and e go to ETC - e move down protein complexes with higher affinity. Each H released by NADH, 4 protons pumped across into inter membrane space.
3.e accepted by final acceptor oxygen, plus hydrogen forming water. - Pumping of protons creates proton gradient , so they move through protein channel.
This provided energy for ATP synthase to produce ATP.
Where does the light dependent reaction take place?
Thylakoid membrane
Where does the light independent reaction take place?
Stroma
Where does the link reaction occur ?
Mitochondrial matrix
Where does the krebs cycle occur ?
Mitochondrial matrix
Where does oxidative phosphorylation occur ?
Mitochondria
