Cellular Energy Flashcards
Name 3 processes that cells require energy for.
Movement, synthesis, maintenance (homeostasis)
How do photo-autotrophs create chemical energy?
Convert light energy into chemical energy through photosynthesis
How to chemo-autotrophs create energy?
Produce organic molecules from carbon dioxide through oxidation (chemosynthesis)
Why must waste materials be removed?
Waste substances could cause toxicity to the cells.
How to organisms identify when to remove waste materials?
Organisms have tolerance limits for these waste materials, controlled by homeostasis feedback mechanisms to ensure these substances are removed.
How do animals and unicellular organisms remove waste?
Animals: specialised excretory systems.
Unicellular organisms: excrete waste directly into environment via diffusion.
How do plants remove waste?
Plants: no dedicated excretory system - excess water is removed through transpiration, oxygen is removed via diffusion through leaves into the atmosphere, other waste products are stored in cells, and can be lost when leaves are dropped
Compare the chemical reaction of photosynthesis and aerobic respiration.
Products and reactants are reversed.
Photosynthesis: carbon dioxide + water»_space; glucose + oxygen.
Aerobic respiration: glucose + oxygen»_space; carbon dioxide + water + ATP
Define photosynthesis.
A series of reactions in the chloroplasts which convert sunlight, carbon dioxide and water into glucose and oxygen.
How does photosynthesis work?
Chlorophyll captures energy from sunlight and uses it to react water (from roots) and carbon dioxide (from leaves) to make sugar, along with oxygen (waste product, realsed from leaves)
How is glucose used?
Energy to grow and reproduce, any unused glucose is stored as a carbohydrate in leaves, stem and roots
Chemical equation for photosynthesis.
6CO2 + 6H2O»_space; + light & chlorophyll»_space; C6H12O6 + 6O2
Define aerobic respiration.
A process that uses oxygen to break down glucose and oxygen to release ATP energy, with carbon dioxide and water as waste products
Do plants breathe?
No, because plants do not use muscles to draw in air, they don’t breathe, but they do respire (passive exchange of gas)
Compare the role of oxygen and carbon dioxide in photosynthesis and respiration.
Photosynthesis uses carbon dioxide and releases oxygen.
Respiration uses oxygen and produces carbon dioxide.
Where does photosynthesis, aerobic respiration and anaerobic respiration occur?
Photosynthesis: chloroplasts (plant cells).
Aerobic respiration: primarily in mitochondria.
Anaerobic respiration: cytoplasm
What are the two types of fermentation, and in which organisms do they each occur?
Alcoholic fermentation: plants and fungi.
Lactic acid fermentation: animals and bacteria.
What is the raw material for both types of fermentation?
Glucose
What is the product of each type of fermentation?
Alcoholic: carbon dioxide + ethanol.
Lactic acid: lactic acid
Define anaerobic respiration.
A process that produces energy from glucose in the absence of oxygen
Why is anerobic respiration (fermentation) less efficient than aerobic respiration?
Aerobic: creates approximately 36 ATP molecules per glucose molecule.
Anaerobic: creates approximately 2 ATP molecules per glucose molecule
