Cellular Respiration/ Photosynthesis Flashcards
Which organisms undergo cell resp?
All
What is ATP used for? (4)
Active transport, movement of cilia/flagella, muscle contraction, and synthesizing compounds
What is the difference between ATP and ADP?
ATP has 3 phosphates while ADP has 2.
What stage(s) during cell resp is classified as substrate-level phosphorylation?
Glycolysis and the Krebs cycle.
What stage(s) during cell resp is classified as oxidative phosphorylation?
Electron Chain Transport/ Chemiosmosis
Does NAD+ get reduced or oxidized to form NADH+H+?
Reduced
Does NADH+H+ get reduced or oxidized to form NAD+ ?
Oxidized
How many ATPs are generally made during Cell Resp?
36 ATPs
Which part of the mitochondria folds to form cristae?
Inner membrane
What is the space between the outer and inner membrane of the mitochondria called?
Intermembrane space
What is the central fluid of the mitochondria called? Where is it found?
Matrix, found inside the inner membrane.
Why is the cristae highly folded?
So larger surface area for many electron transport chains and proton pores such as Atpase.
Why does the intermembrane space have a small volume?
So protons will accumulate here with a high concentration.
What does the fluid matrix contain that helps in its function?
It contains enzymes and intermediates for the Krebs cycle.
What type of reactions are used throughout cell rep to strip the energy from glucose?
Redox reactions (reduction/oxidation)
What is oxidation?
A lose of electrons/hydrogens. A gain of oxygen.
What is reduction?
A gain of electrons/hydrogens. A loss of oxygens.
What do you call an electron acceptor?
Oxidizing agent
What do you call an electron donor?
Reducing agent
When an electron is transferred, what is released?
Energy
Is glycolysis anaerobic or aerobic?
anaerobic
What is the pathway of anaerobic respiration?
Glycolysis then fermentation.
What is the net production of glycolysis?
2 pyruvic acid (pyruvate), 2 ATP (4 made but 2 net), 2 NADH+H+
What is glucose converted into in the first step of glycolysis? What is required for this step to occur?
Fructose diphosphate and it requires 2 ATP molecules
What process occurs when glucose is converted into fructose diphosphate?
Phosphorylation
Why is TP produced?
Fructose diphosphate is an unstable molecule so it falls apart into 2 x 3 carbon triose phosphate.
What is produced when TP changes into G3P?
one NADH+H+ per TP molecule
What is produced when G3P is converted into pyruvate?
2 ATP molecules per G3P molecule
How many ATP molecules does one NADH +H+ molecule yield?
2 ATP molecules
What is needed for pyruvate to be transported by a carrier protein into the mitochondrial matrix?
Oxygen
What happens if no oxygen is present after glycolysis?
Pyruvate is fermented to make lactate (or ethanol and carbon dioxide in yeast)
What, if not available, will grind glycolysis to a halt?
NAD+
Why did anaerobic cell resp evolve in organisms?
As a way of recycling NAD+
What happens during lactate fermentation? Where does it occur?
NADH+H+ transfers two hydrogens to pyruvate in the cytoplasm
Where does glycolysis occur in the cell?
In the cytoplasm
When pyruvate gains 2 hydrogens, what is it called?
Lactate/ lactic acid
What happens during alcohol fermentation?
Pyruvate changes to ethanal and carbon dioxide. Ethanal then gains the two hydrogens from NADH+H+ to produce ethanol
Will yeast do some fermentation even when oxygen is present?
Yes.
What do respirometers measure?
Simple respirometers measure volume changes due to oxygen use.
How do you eliminate the CO2 produced when using a respirometer?
Add an alkali (KOH, NaOH, soda lime) which can absorb any CO2 produced
Does the Krebs cycle require oxygen? Where does it occur?
Yes, occurs in the mitochondrial matrix.
What occurs in the pyruvate link reaction? What is the end product?
One pyruvate is decarboxylized (a carbon dioxide is released as waste) and an NAD+ gains 2 hydrogens and 2 electrons from pyruvate. Pyruvate is converted into acetic acid by the end.
How is acetyl-CoA made? What enters the krebs cycle?
The acetic acid in the link reaction attaches to coenzyme A. Acetyl-CoA enters the krebs cycle.
If acetyl-CoA is two carbons, how is the 6 carbon citric acid molecule made at the start of the cycle?
Acetyl-CoA attaches to the 4 carbon oxaloacetate that is at the end of the cycle.
When citric acid becomes a 5c molecule, what is produced?
NADH+H+, CO2
What is the net production of the krebs cycle including the link reaction? (per pyruvate molecule)
4 x NADH+H+, 1 x FADH2, 1 x ATP, 3 x CO2
How many times does the krebs cycle run per glucose molecule?
Twice
Where does ETC occur?
On the inner membrane (cristae)
When electrons are pulled to stronger electron acceptors in the ETC, what is the final electron acceptor and what does it produce?
Oxygen is the last electron acceptor and produces water.
What is the energy produced by electrons transferring in the ETC chain used for?
To pump protons into the intermembrane space.
Name two hydrogen carriers.
NADH+H+ and FADH2
What pathway do poisons usually block in cell resp?
The ETC pathway
What is chemiosmosis? Name an example.
The movement of ions across a selectively permeable membrane down their concentration gradient. Hydrogen moving through ATpase to make ATP. It goes from higher concentration to lower concentration.
Where do the hydrogens concentrate during the ETC step of cell resp?
In the intermembrane space of the mitochondria
What process is the energy from protons moving down ATPase used for?
The phosphorylation of ADP to produce ATP.
How many ATPs can NADH+H+ from glycolysis produce?
2
How many ATPs can NADH+H+ from the krebs cycle produce?
3
How many ATPs can FADH2 from the krebs cycle produce?
2
What is the photosynthetic organ of the plant?
The leaf
Which part of the leaf collects sunlight?
The blade
What is two examples of ground tissue in a plant?
Palisade mesophyll and spongy mesophyll.
What is the function of the palisade mesophyll?
Carries out photosynthesis.
What is stored in the spongy mesophyll? What other function does it conduct?
Water and dissolved gases are held. The spongy mesophyll also distributes CO2 and O2 throughout the leaf
What does the xylem transport?
Water/minerals
Does the spongy mesophyll carry out gas exchange with its environment?
Yes
What does the phloem transport?
Sugars
What are some dermal tissues? (3)
Epidermis, cuticle, stomata (which is controlled by guard cells
What sturcture has pores to allow for gas exchange?
Stomata
What is the role of the guard cells? (2)
Controls opening of stomata and can also photosynthesize.
Which organelle is responsible for photosynthesis?
The chloroplast
What is in a palisade cell?
100s of chloroplasts
Draw the chloroplast.
What is the solution in the chloroplast called?
Stroma
What is the membrane system that consists of flattened sacs in the chloroplast called?
Thylakoid
What is a stack of thylakoid called?
Grana
How many separate membranes does the chloroplast contain?
3
What are the three spaces in the chloroplast called?
Intermembrane space, stroma, and thylokoid space (lumen)
Is ATP produced during photosynthesis?
Yes
Is CO2 oxidized or reduced to form glucose?
Reduced
What colour is chlorophyll a?
Blue-green
What colour is chlorophyll b?
Yellow-green
What two colours do leaves absorb well?
Red and Blue
What colour do leaves reflect most?
Green
Can leaves absorb some green light?
Yes, accessory pigments like carotenoids can use green light to photosynthesize
Draw absorption spectrum and action spectrum for photosynthesize.
Where does the light-dependent reaction occur?
In the thylakoid membrane.
Where are the pigments located in the chloroplast?
In the thylakoid membrane
What is a photosystem a cluster of?
Chlorophyll and other pigments.
When a photosystem absorbs light, where is the energy passed to?
The reaction centre which is a chlorophyll a or b molecule.
What is the key to photosynthesis?
The fact that energy is harnessed during the electron chain.
How can a pigment emit light when it is excited by light?
If an excited electron jumps to a higher energy level and then drops back to ground state.
What starts of the light dependent reaction?
Photolysis, light splits a water molecule so that two electrons travel to PS2 to fill the gap
What is the waste product of photolysis?
Oxygen
Where do protons accumulate during the light-dependent reaction?
In the lumen of the thylakoid.
What type of light energy does PS2 absorb?
P680
What type of light energy does PS1 absorb?
P700
When is ATP produced during photosynthesis? What is the process called? When is this ATP used?
During the electron transport system. Process is called phosphorylation. This ATP is used in the Calvin-Benson cycle.
Where does the electron of the electron transport system during photosynthesis end up?
Fills the gap in PS1.
What is the final electron acceptor?
NADPH
Where does the light independent reaction take place?
In the stroma of the chloroplast
At the start of the calvin benson cycle, what does CO2 bind to? What enzyme helps?
RuBP with the help of RuBisCO
Why does GP form?
The RuBP and CO2 molecule is unstable and falls apart.
What is needed for GP to convert into TP?
12 ATP molecules and 12 NADPH+H+ molecules.
How many TPs leave to form glucose? How many turns of the calvin benson cycle is required for that?
2 TPs leave and 6 turns are required
What do the majority of the TP molecules remain in the cycle to do?
To help reform RuBP
What does TP use to turn into RuBP?
6 ATP
What are three ways used to measure the rate of photosynthesis?
Production of oxygen, uptake of CO2, indirectly by the increase in mass of the plant
How do you measure the uptake of carbon dioxide? (2)
Using a CO2 probe or change in pH
How do you measure the production of oxygen?
Counting bubbles, oxygen probes, volume displacement
What are three limiting factors of photosynthesis?
Light, CO2, Temperature
Is water a limiting factor of photosynthesis?
No
