3A3 Matter and Energy Flow in Organisms Flashcards
Explore how matter and energy flows in organisms through biochemical processes and biomolecules. (52 cards)
What is cellular respiration?
The process by which cells convert glucose into energy.
Cellular respiration generates ATP by breaking down glucose molecules, with or without oxygen.
What are the two main types of cellular respiration?
- Aerobic Respiration
- Anaerobic Respiration
Aerobic respiration requires oxygen and occurs in plants, animals, and fungi. Anaerobic respiration occurs without oxygen, and usually occurs in bacteria, archea, and other small microorganisms.
However, in situations of low oxygen, humans and plant cells can undergo anaerobic respiration.
Fill in the blank:
Aerobic respiration occurs in the __________.
mitochondria
Aerobic respiration primarily takes place in the mitochondria where oxygen is utilized for ATP production.
What is the main purpose of aerobic respiration?
To produce ATP using oxygen.
This process is highly efficient, yielding up to 38 ATP molecules per glucose molecule.
True or False:
Anaerobic respiration occurs in the mitochondria.
False
Anaerobic respiration occurs in the cytoplasm since it does not require the organelles involved in oxygen-dependent processes.
What is the main purpose of anaerobic respiration?
To generate energy without oxygen.
This process produces less ATP (2 ATP per glucose) but is faster than aerobic respiration.
What is the chemical equation for aerobic respiration?
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP
Glucose and oxygen are converted into carbon dioxide, water, and energy in the form of ATP.
Fill in the blanks:
Anaerobic respiration produces _______ or _______ as by-products.
lactic acid ; ethanol
Ethanol and CO₂ are by-products in yeast. When humans (and other animals) exercise strenuously, the cells do not have enough oxygen to produce energy, so lactic acid is produced.
What are the 3 stages of aerobic respiration?
- Glycolysis
- The Krebs cycle
- Electron Transport Chain
These stages collectively produce ATP and require oxygen.
What is glycolysis?
The breakdown of glucose into pyruvate.
It occurs in the cytoplasm and is the first step in both aerobic and anaerobic respiration.
True or False:
Glycolysis requires oxygen.
False
Glycolysis is an anaerobic process and can occur with or without oxygen, which is why it is the first step for both aerobic and anaerobic respiration.
Where does the Krebs cycle occur in the cell?
In the mitochondrial matrix.
This cycle processes pyruvate to produce energy-rich molecules like NADH and FADH₂.
What is the main role of the electron transport chain?
To generate ATP using high-energy electrons.
This step uses oxygen as the final electron acceptor to produce ATP.
Fill in the blank:
Oxygen acts as the final ________ ________ in the electron transport chain.
electron acceptor
Oxygen combines with electrons and protons to form water, completing the process. This explains why oxygen is necessary for aerobic respiration.
What is fermentation?
An anaerobic process that breaks down sugar to produce energy.
This process is a type of anaerobic respiration seen in organisms like yeast and muscle cells under low oxygen conditions.
What are two types of fermentation?
- Alcoholic fermentation
- Lactic acid fermentation
Alcoholic fermentation – Produces ethanol and CO₂ (e.g., yeast).
Lactic acid fermentation – Produces lactic acid (e.g., muscles, yogurt bacteria).
True or False:
Fermentation requires oxygen to produce energy.
False
Fermentation is anaerobic, meaning it occurs without oxygen. It allows organisms to generate ATP when oxygen is unavailable.
What is the ATP yield of anaerobic respiration?
2 ATP per glucose molecule.
Anaerobic respiration makes less energy when compared to aerobic respiration, but is a much quicker process.
What gas is released during aerobic respiration?
Carbon dioxide
(CO₂)
CO₂ is released during the Krebs cycle and is expelled during exhalation.
What happens to pyruvate in aerobic respiration?
It enters the Krebs cycle.
In aerobic conditions, pyruvate is converted to acetyl-CoA and processed further in the mitochondria.
What is the primary energy carrier molecule produced during respiration?
ATP
(Adenosine Triphosphate)
This molecule provides energy for cellular processes.
What is photosynthesis?
The process by which plants convert sunlight into chemical energy.
This process occurs in chloroplasts, using light, water, and carbon dioxide to produce glucose and oxygen.
Where does photosynthesis primarily occur in plants?
In the chloroplasts of leaf cells.
Chloroplasts contain chlorophyll, which captures light energy essential for photosynthesis.
What is the main molecule that absorbs light energy for photosynthesis?
Chlorophyll
This molecule absorbs light, primarily in the blue and red wavelengths, while reflecting green light.