Photosynthesis and Respiration-Topic 5A Flashcards
Name the 2 types of respiration
Aerobic (requires oxygen) and Anaerobic (doesn’t require oxygen)
Which type of respiration produces less ATP?
Anaerobic
What does Glycolysis involve?
Splitting 1 molecule of glucose (6C) into 2 smaller molecules of pyruvate (3C)
Where does Glycolysis occur?
In the cytoplasm of cells.
Glycolysis is the …. stage of both ….. and ….. respiration.
Glycolysis is the first stage of both aerobic and anaerobic respiration.
Does Glycolysis require oxygen to take place?
No therefore it’s an anaerobic process.
Name the 2 main stages in Glycolysis
- Phosphorylation
2. Oxidation
What is ATP used for in Glycolysis?
To phosphorylate glucose to triose phosphate.
What happens once triose phosphate has been formed during the calvin cycle
It is then oxidised which releases ATP .
What is the net gain in Glycolysis?
2 reduced NAD and 2 ATP
When triose phosphate is oxidised it …… .. ……
When triose phosphate is oxidised it loses 2 Hydrogen.
In Anaerobic respiration what is Pyruvate converted to using reduced NAD?
Ethanol ( plants/yeast) or Lactate ( animals/ some bacteria)
What does decarboxylation mean?
Carbon atom removed in the form of CO2
What does the Link reaction do?
Converts pyruvate to acetyl coenzyme A
List the stages of the Link reaction
- Pyruvate decarboxylated
- Pyruvate oxidised to form acetate and NAD is reduced to REDUCED NAD
- Acetate combines with coenzyme A to form acetyl coenzyme A.
Is ATP produced in the Link Reaction?
No!
How many times does the Link reaction occur for every glucose molecule?
Twice
What does the Krebs cycle produce?
Reduced Coenzymes and ATP.
Within the Krebs Cycle what is occurring when the Hydrogen is removed?
Dehydrogenation
What is ATP produced by?
The direct transfer of a phosphate from an intermediate, to ADP.
What is it called when a phosphate group is directly transferred from one molecule to the other?
Substrate-level phosphorylation.
What does Oxidative Phosphorylation do?
Produces lots of ATP
What is the process of oxidative phosphorylation?
The energy carried by electrons, from reduced coenzymes is used to make ATP.
What does oxidative phosphorylation involve?
The electron transfer chain and chemiosmosis.
What is produced by the Link Reaction?
2 x CO2
2 x reduced NAD
2 x Acetyl coenzyme A
What happens if during Oxidative Phosphorylation, there isn’t any oxygen present?
It cannot accept electrons therefore no more ATP can be produced as the electron transfer chain stops running.
Where does the light-independent reaction occur?
In the stroma of chloroplasts
What is photolysis?
Photolysis is the splitting of water with light
What is Photosynthesis?
A reaction in which light energy is used to produce glucose in plants
What is the rate of photosynthesis determined by?
The CO2 concentration, light intensity as well as temperature.
How are chloroplasts adapted for photosynthesis?
Contain DNA + ribosomes for synthesis of proteins needed for LDR.
Stacks of thylakoid membranes called grna = large SA for attachment of electrons,enzymes and chlorophyll.
Where does the energy come from for photosynthesis
Energy stored as chemical energy in phosphate bond of ATP ( released when hydrolysed to ADP )
What does chlorophyll do and where can it be found?
Absorbs light energy for photosynthesis. Found in thylakoid membranes.
What is stroma and where can it be found?
Within the inner membrane, a gel-like substance containing enzymes, sugars and organic acids.
Name the 2 stages that Photosynthesis can be split into
LDR AND LIR (Calvin cycle)
The energy resulting from the photoionisation of chlorophyll is used for what 3 things?
Making ATP from ADP and Pi (photophosphorylation)
Making reduced NADP from NADP
Splitting water into protons, electrons and oxygen (photolysis)
Name the structures that can be found within a chloroplast
Lamella Grana Stroma Thylakoid Thylakoid membrane (chlorophyll inside) Inner/outer membrane starch grain
Name the structures that can be found within a chloroplast
Lamella (links grana together) Grana Stroma Thylakoid Thylakoid membrane (chlorophyll inside) Inner/outer membrane starch grain
Where does the LDR take place?
Thylakoid membranes of chloroplasts
What does the process of electrons flowing down the transport chain do?
Creates a proton gradient across the membrane. (This whole process is also called chemiosmosis)
The calvin cycle relies on products from ….. …..-….. …..
the light-dependent reaction
Where does the calvin cycle take place?
Stroma
Describe how leaves having a large SA is an adaption for Photosynthesis.
Gases can be exchanged more efficiently and the sunlight is more largely absorbed.
Describe how a Thin Upper Epidermis is efficient for Photosynthesis.
Faster gas exchange due to a shorter diffusion pathway.
Describe how the position of Chloroplasts could be an adaptation for Photosynthesis.
Arranged to top of leaf for maximum light absorption
Describe how substomatal air space could be an adaptation of Photosynthesis.
Air spaces to allow rapid diffusion of gases in spongy mesophyll.
Describe how the non-overlapping leaf structure is beneficial to photosynthesis.
Avoids shadowing of one leaf with another.
How is having a transparent cuticle beneficial to Photosynthesis?
This allows light through to the mesophyll cells.
What is chlorophyll?
pigment which absorbs light
List properties of ATP
small +soluble, easily broken down, rapidly re-synthesised, it can activate other molecules e.g. addition of phosphate.
What is photoionisation?
light energy “excites” an electron + releasing it.
What is dehydrogenation?
The removal of hydrogen from a molecule
What is the purpose of NADP in Photosynthesis?
Transfers H from molecule to molecule to reduce/oxidise a molecule.
Reduce
Give hydrogen to
Oxidise
Take hydrogen from
Name the 2 photosystems used by plants to capture light energy
PSI and PSII
Name 3 limiting factors for Photosynthesis
Light intensity, Temperature, and CO2
What are the optimum conditions for photosynthesis?
25*c (above 45 denature, below 10 = inactive enzymes)
0.4% CO2
What does the Calvin Cycle produce?
Triose Phosphate
What is the product of the Calvin cycle used for?
Making glucose and other organic substances.
The reactions in the Calvin Cycle are linked which means the start product ……… …….. is ………..
The reactions in the Calvin Cycle are linked which means the start product ribulose bisphosphate is regenerated.
What is the name of the enzyme in the Calvin Cycle?
Rubisco
How many TP molecules are converted into hexose sugars?
1/6
Glycerate 3-phosphate (GP) is reduced to triose phosphate (TP) by which two molecules?
ATP
Reduced NADP
What is the final stage of aerobic respiration?
oxidative phosphorylation
List the 4 processes, in order, that occur in respiration.
Glycolysis–The Link Reaction–The Krebs Cycle–Oxidative Phosphorylation
Name the structures that can be found within a mitochondria
Matrix Cristae Inter-membrane space Outer membrane Inner Membrane ATP Synthase
Where does the Link reaction occur?
Matrix of mitochondria
In oxidative phosphorylation, what molecule is the final electron acceptor?
Oxygen
How can there still be uptake of CO2 when stomata are covered?
CO2 uptake through cuticle
Why does the uptake of CO2 by plants become 0 when lights are turned off? [2]
No CO2 needed for photosynthesis as it’s dark
No diffusion gradient maintained for CO2 to enter the leaf.
Suggest and explain why the rate of photosynthesis was low between certain wavelengths of light [2]
More reflection of these wavelengths
Could be the same as green light/ colour of chlorophyll
Name the 3 main stages of photosynthesis
Capturing Light energy
LDR
Calvin Cycle
Describe Chemiosmosis
Process of electrons flowing down electron transfer chain establishing proton gradient across membrane to drive ATP synthesis.
