Photosynthesis Flashcards
Why do plants need energy? (4)
⦾ Photosynthesis (1)
⦾ AT (1)
⦾ DNA replication (1)
⦾ Cell division (1)
Why do animals need energy? (4)
⦾ Muscle contraction (1)
⦾ Body temp maintenance (1)
⦾ DNA replication (1)
⦾ Cell division (1)
Photosynthesis equation? (1)
⦾ 6CO2 + 6H2O → C6H12O6 + 6O2 (1)
Why is photosynthesis an example of a metabolic pathway? (1)
⦾ Occur in small series of reactions (controlled by enzymes) (1)
Respiration equation? (1)
⦾ C6H12O6 + 6O2 → 6CO2 + 6H2O (1)
2 types of Respiration? (2)
Give the equations for the 2 different places the 2nd type occur? (2)
⦾ Aerobic - with Oxygen (1)
⦾ Anaerobic - with/o Oxygen (1)
- Plants + Yeast → Ethanol + CO2 (1)
- Humans → Lactate energy (1)
ATP stands for? (1)
What is it? (1)
⦾ Adenosine TriPhosphate (1)
⦾ Store of energy (1)
ATP structure? (3)
⦾ Nucleotide base Adenine (1)
⦾ Ribose sugar (1)
⦾ 3 x Phosphate groups (1)
ATP properties?
- Stores/releases small energy amounts - reduce heat loss energy (1)
- Small soluble molecule - easily transported (1)
- Easily broken down - instantaneous energy release (1)
- Quickly remade (1)
- Phosphorylation - Added to other molecules to make more reactive by transferring 1 X its Pi groups (1)
- Can’t pass out cell - Always immediate energy supply (1)
Where does photosynthesis occur? (1)
⦾ Chloroplast (1)
What are the different structures of chloroplast? (6)
⦾ Grana - Stacked thylakoid (1)
⦾ Lamellae - Link Grana (1)
⦾ Photosynthetic pigments (1) - Coloured substances that
absorb light energy
- Inside thylakoid membrane
e.g. Chlorophyll a/b
⦾ Photosystems - Protein + Pigment: PSI (700nm) + PSII (680nm) (1)
⦾ Stroma - contains enzymes + sugars (1)
⦾ Starch - Stored carbohydrates (1)
Explain ‘REDOX’? (3)
⦾ Reduction Is Gain of Electrons, Addition of H + Loss of O2 (1)
⦾ Oxidation Is Loss of Electrons, Loss of H + Gain of O2 (1)
⦾ Occurs simultaneously (1)
Define Coezymes and give an example? (1)
⦾ Molecules aid enzyme function (1)
⦾ by transferring chemical groups from one molecule to another (1)
e.g. NADP transfers H
Give a short summary of the Light-Dependent reaction?
7
⦾ Requires light (1)
⦾ Occurs: thylakoid membrane of chloroplasts (1)
⦾ Photoionisation occurs: (1)
⦾ Chlorophyll absorbs light energy → excites e-s (1)
⦾ High energy e-s released from chlorophyll (1)
⦾ Chlorophyll’s now a +ve ion (1)
⦾ Uses of the energy: ADP + Pi → ATP (1)
NADP → NADPH
Give a short summary of the Light-Independent reaction? (3)
⦾ Relies on LDR products (1)
⦾ Occurs: Stroma (1)
⦾ ATP + NADPH provide energy + H to make glucose (1)
Energy uses of Photoionisation? (3)
⦾ Photophosphorylation ADP + Pi → ATP (1)
⦾ NADP → NADPH (1)
⦾ Photolysis of water into: H+, Electrons + O2 (1)
What are electron carriers? (1)
What do they do? (1)
⦾ Proteins linking photosystems (1)
⦾ Transfer electrons (1)
What are electron transport chains? (1)
What flows through them?(1)
⦾ Photosystems + electron carriers (1)
⦾ excited electrons (1)
Explain fully the process of the Light-Dependent reaction/Non-cyclic photophosphorylation? (11)
- PSII absorbs light energy → excites e-s in chloropyll (1)
2.Excited e-s move to higher energy level. (1) - ## High energy e-s released from chlorophyll + move down ETC to PSI (1)
- Excited e-s which left PSII must be replaced. (1)
- Photolysis - light energy splits water into:
☉ H+, Electrons + O2 (H2O → 2H+ + 1/2O2) (1)
——————————————————————————— - Excited e-s lose energy moving down ETC + energy’s used to transport H+ to thylakoid + create higher proton (H+) conc in thylakoid than stroma. (1)
- Proton (H+) conc. grad. across thylakoid membrane (1)
- ## Protons (H+) move down conc. grad. into stroma via ATP synthase (1)
- ## Energy from movement combines ADP + Pi → ATP (1)
- PSI absorbs light energy + excites e-s to higher energy level(1)
- e-s transferred to NADP (and a H+) to form → NADPH (1)
Define chemiosmotic theory? (3)
⦾ Process of e-s flowing down ETC (1)
⦾ creating proton grad. across membrane to (1)
⦾ drive ATP synthesis. (1)
What is Cyclic Photophosphorylation? (4)
⦾ ‘Cyclic’ - e-s from chlorophyll not passed onto NADP but back to PSI via e- carriers (1)
⦾ Only PSI used + ATP produced (1)
⦾ Therefore, e-s recycled + flow through PSI (1)
⦾ No NADPH/O2 produced - only small amounts of ATP (1)
What 2 products does the Light-Independent reaction require from the Light-Dependent reaction? (2)
⦾ ATP (1)
⦾ NADPH (1)
Where does the Light-Independent reaction occur? (1)
⦾ Stroma (1)
What is the overall reaction for the Light-Independent reaction? (1)
⦾ RuBP (5C) + CO2 → TP (3C) (1)
Why is the Light-Dependent reaction a ‘cycle’? (1)
⦾ RuBP regenerated (1)
What can the Light-Dependent reaction also be called? (1)
⦾ The Calvin Cycle (1)
What do the following stand for/mean? ⦾ Rubisco (1) ⦾ GP (1) ⦾ RuBP (1) ⦾ TP (1)
⦾ Rubisco - enzyme (1)
⦾ GP - gylcerate-3-phosphate (3C) (1)
⦾ RuBP - Ribulose biphosphate (5C) (1)
⦾ TP - Triose phosphate (3C) (1)
The Light-Independent reaction/Calvin Cycle:
Explain the formation of glycerate-3-phosphate? (3)
- CO2 enters stomata + diffuses to stroma (1)
- Combines with RuBP and rubisco (1)
- Forms: unstable 6C compound which breaks down into 2 X GP (1)
What is the overall equation for the formation of gylcerate-3-phosphate? (1)
⦾ RuBP (5C) + CO2 + Rubisco → Unstable 6C compound → 2 X GP (3C) (1)
The Light-Independent reaction/Calvin Cycle:
Explain the formation of triose phosphate? (3)
- ATP from LDR hydrolised to provide energy to reduce
GP → TP (1) - NADPH is recycled to NADP to provide H+ for reaction (1)
- TP has many uses - glucose - regenerate RuBP (1)