Ecosystems rely on energy transfer T5/photosynthesis. Flashcards
Name the two elements needed to make proteins that are not present in glucose.
(2)
- Nitrogen
- Sulfur
Name the two elements needed to make nucleic acids that are not present in glucose.
(2)
- Nitrogen
- Phosphorus
Which molecule provides the source of hydrogen for photosynthesis?
-H20
What is the source of energy for photosynthesis?
-Light
Which molecule provides the hydrogen for the light independent reactions?
-Reduced NADP
Which molecule provides the energy for the reduction of carbon dioxide to glucose in the light-I reactions?
-ATP
Where does the light-dependant reaction take place?
The thylakoid membranes of chloroplasts.
Where does the light-independent reaction take place?
The chloroplast stroma.
Plant fibres and oil-based plastics have both been used to make ropes.
Describe one advantage and one disadvantage of using ropes made from plant fibres rather than ropes made from oil-based plastics.
(2)
- Advantage: is sustainable /biodegradable / can decompose.
- Disadvantage: less strong /can decompose/ is biodegradable.
Plant cell walls contain cellulose. Name the monomer that makes up cellulose.
(1)
Beta-glucose
How are the beta-glucose monomers held together in a cellulose molecule?
(1)
-By glycosidic bonds in an unbranched chain.
Photosynthesis is a two-stage process by which plants fix carbon dioxide.
Describe the light-dependent reactions of photosynthesis.
(5)
- Use of light energy to excite electrons in chlorophyll/ photosystem 1 and 2/electrons promoted to higher energy level.
- Photolysis of water to produce oxygen, electrons and hydrogen ions.
- Electrons used in the electron transport chain/ to replace those lost by chlorophyll/ electrons used in redox reactions/ move along electron carrier proteins.
- Generation of ATP/ photo-phosphorylation.
- Reduction of NADP.
Describe the structure of a cellulose cell wall.
3
- Cellulose molecule is a polymer/ chain of beta-glucose molecules.
- Cellulose molecules held together by hydrogen bonds as microfibrils.
- Microfibrils arranged in parallel/ criss cross.
- Ref. to hemicelluloses.
Write an equation summarising:
- The splitting of water
- The reduction of NADP
a) H20=2H and 2e- and 1/2 O2
b) 2H+ and 2e- and NADP = reduced NADP
Which enzyme catalyses the breakdown of ATP to ADP?
1
-ATPase