Biology - Review Qns - 5 Flashcards
What are the 2 stages of Photosynthesis?
1) light-dependent reactions
2) light-independent reactions.
What do Chloroplasts contain?
4 Items
Thylakoid membranes
Grana
Stroma (fluid)
Their own DNA and ribosomes
Where do the light dependent reactions occur?
On the grana
What are the light dependent reactions?
3 steps
Light energy is trapped by chlorophyll
Water is split
Oxygen is released as a product.
Where do the light independent reactions occur?
In the stroma
What are the light indepent reactions?
Carbon dioxide is reduced to form glucose
Write the balanced chemical equation for photosynthesis.
6 CO₂ + 6 H₂O → C₆H₁₂O₆ + 6 O₂
Key Factors afecting rate of photosynthesis?
3 Key Factors
- An increase in carbon dioxide levels can increase the rate of photosynthesis.
- An increase in light intensity can increase the rate of photosynthesis.
- The availability of chloroplasts to carry out photosynthesis can
What happens outside optimum temperature range for phtosynthesis?
Too cold → rate of reaction will be too slow.
Too hot → enzymes in chloroplasts can denature
What happens when stomata close?
Plant can no longer exchange oxygen and carbon dioxide,
→ the rate of photosynthesis decreases.
What is the benefit of closing its stomata?
Minimizes water loss
Which organic molecule is used as the primary source of energy for most cells?
Glucose
What does ATP do?
The energy released in the breakdown of glucose is carried by ATP.
What is Glycosis?
The first stage of cellular respiration.
How many ATP molecules can be created from one glucose molecule during glycolysis?
Two ATP (per glucose molecule) are created during glycolysis
What are the stages of aerobic cellular respiration?
3 stages
Glycolysis
The Krebs cycle
The electron transport chain.
What are the contents of Mitochondria?
3 components
Cristae (folded membranes)
Matrix (fluid)
Their own circular DNA (mtDNA) and ribosomes.
Details on Glycosis
Location
Product
Reaction
Glycolysis occurs in the cytosol
Glycolysis yields 2 ATP.
Glucose is converted into two pyruvate molecules.
Details on Krebs cycle
Location
Product
Reaction
Occurs in the matrix of the mitochondria
Yields 2 ATP.
Pyruvate is broken down into carbon dioxide.
Details on electron transport chain
Location
Product
Reaction
Occurs in the cristae of the mitochondria
Yields 26–28 ATP.
Oxygen accepts the hydrogen ions that are used to generate a large amount of energy
Product of anaerobic respiration in animals?
Lactic Acid
Product of anaerobic respiration in yeast?
Ethanol and Carbon Dioxide
Eficiency of Aerobic vs Anaerobic respiration?
ATP of Aerobic vs Anaerobic
Aerobic respiration yields 30–32 ATP per glucose molecule
Anaerobic respiration yields 2 ATP per glucose molecule
What is the effect of temperature on cellular respiration?
When the temperature is above or below the optimum range, the rate of cellular respiration is slower.
Below optimum: insufficient energy to activate
Above optimum: protiens start to denature
