Topic 5A - Photosynthesis and Respiration Flashcards
What biological processes do PLANTS need energy for?
- Photosynthesis
- Active transport (to take in minerals via the roots)
- DNA Replication
- Cell Division
- Protein synthesis
What biological processes do ANIMALS need energy for?
- Muscle contraction
- Maintaining internal body temperature
- Active transport
- DNA Replication
- Cell Division
- Protein synthesis
What would happen if a plant/animal didnt receive any energy?
Biological processes would stop and the plant would die
What is photosynthesis?
Photosynthesis is a process where energy from light is used to make glucose from H20 and CO2
- light energy is converted to chemical energy in the form of glucose
What is the photosynthesis equation?
6C02 + 6H20 + energy ——– C6H1206 + 602
Where is energy stored after photosynthesis takes place?
It is stored in the glucose until it is released/used up in respiration
How do animals obtain glucose?
Animals obtain glucose by eating plants (or other animals)
What are the 2 types of respiration?
- Aerobic respiration
2. Anaerobic respiration
What is the equation for aerobic respiration?
C6H1206 + 602 —— 6C02 + 6H20 + energy
What does anaerobic respiration produce in:
1- plants?
2- animals?
- In plants + yeast, it produces C2H50H (ethanol) + CO2
2. In animals, it produces lactate
What are 6 useful properties of ATP?
- Stores/releases small,manageable amount of energy at a time, so no energy wasted as heat
- Small and soluble so easily transported around cell
- Easily broken down so energy released instantly
- It can be quickly re-made
- Can Make compound more reactive - phosphorylation
- Can’t pass out cell - immediate energy supply
Define these 4 key words:
- Metabolic Pathway?
- Phosphorylation?
- Photophosphorylation?
- Photolysis?
- Metabolic Pathway - series of small reactions controlled by enzymes e.g. respiration/photosynthesis
- Phosphorylation - Adding phosphate to molecule
- Photophosphorylation - Phosphorylation using light
- Photolysis - Splitting of a molecule using light energy
Define these next 3 key words:
- Photoionisation?
- Decarboxylation?
- Dehydrogenation?
- Photoionisation - When light energy excites electrons in an atom, giving them energy so that they are released
- Decarboxylation - Removal of CO2 from a molecule
- Dehydrogenation - Removal of H2 from a molecule
- Hydrolysis - splitting of a molecule using water
What are co-enzymes?
A coenzyme is a molecule that aids the function of an enzyme
How do co-enzymes work?
They work by transferring a chemical group from 1 molecule to another
What enzyme(s) is used in photosynthesis and what is its role?
NADP - transfers H2 from 1 molecule to another so that they can reduce or oxidise a molecule
What enzyme(s) is used in respiration and what is its role?
NAD, FAD and coenzyme A
- NAD + FAD transfer hydrogen from 1 molecule to other
- Coenzyme A transfers acetate between molecules
What are photosynthetic pigments and where are they found?
They are coloured substances that absorb light energy needed for photosynthesis (chlorophyll a/b, carotenes)
- They are found in the thylakoid membraned of chloroplasts
What is a photosystem?
The protein and pigment (attached together) in the thylakoid.
What is the main difference between the 2 photosystems used by plants to capture light energy?
Photosystem I (PSI) - absorbs light best at wavelength 700nm
Photosysem II (PSII) - absorbs light best at wavelength 680nm
What does the stroma contain?
The stroma contains enzymes, sugars and organic acids
Where exactly are starch grains stored?
They are stored in the stroma
Name the 2 stages that make up photosynthesis AND where they take place?
(DIAGRAM TO SHOW HOW LIGHT DEPENDENT AND INDENDENT REACTION ARE CONNECTED)
- The light-dependent reaction - thylakoid membranes
2. The light-independent reaction/the calvin cycle/CO2 fixation (as carbon is ‘fixed’ into an organic molecule) - stroma
The energy resulting from the photoionisationof chlorophyll, in the light independent reaction, is used for 3 things. What are they?
- Making ATP during PHOTOPHOSPHORYLATION
- Making reduced NADP from NADP
- Splitting water into protons (H+ ions), electrons and oxygen during PHOTOLYSIS