2.8 Respiration Questions
How do cells capture the energy released by cell respiration?
They produce ATP
Which chemical is produced during both aerobic and anaerobic respiration in humans?
Pyruvate
Many cell functions, like synthesis of macromolecules and transport, require energy in the form of ATP. Explain how ATP is generated in animal cells (8)
-ATP is a form of energy currency/ immediately available for use -ATP is generated in cells by cell respiration (fro organic compounds) -aerobic cell respiration requires oxygen -anaerobic cell respiration does not require oxygen -glycolysis breaks down glucose into pyruvate -glycolysis occurs in cytoplasm -(by glycolysis) a small amount of ATP is released -ADP changes into ATP with the addition of a phosphate group/ phosphoric acid/ accept as chemical equation -in mitochondria/ aerobic respiration produces large amount of ATP/ 38 mols (for the cell, per glucose molecule) -oxygen/ anaerobic respiration is required for mitochondrial production of ATP -in mitochondria/ aerobic respiration pyruvate is broken down into carbon dioxide and water
Outline the process of aerobic respiration. (6)
-During glycolysis glucose is partially oxidised in the cytoplasm --> small yield of ATP is produced -Two pyruvate formed by glycolysis -Pyruvate absorbed into/ broken down in the mitochondrion --> requires oxygen -Carbon dioxide and water is produced in the process -Large ATP yield
Respiration and other processes in cells involve enzymes. Explain the factors that can affect enzymes. (8)
-collisions between enzyme/ active site and substrate -enzyme activity increases as temp rises -more frequent collisions at higher temp -each enzyme has an optimum temp -high temps (above optimum) denature enzymes -each enzyme has an optimum pH -increase or decrease from optimum pH decreases rate of reaction -extreme pH alters enzyme structure -increasing substrate conc increases the rate of reaction -higher substrate conc increases chance of collision -until plateau -when all active sites are busy
Distinguish between the process of anaerobic respiration in yeast and humans. (2)
-yeast: pyruvate to ethanol and carbon dioxide -humans: pyruvate to lactic acid
Distinguish between anaerobic and aerobic cell respiration in eukaryotes. (4)
Aerobic -requires oxygen -(in cytoplasm and) mitochondria -Krebs cycle -large yield of ATP/ energy -CO2 and water (both needed) Anaerobic -no oxygen -in cytoplasm -no Krebs cycle -small yield of ATP -lactate (animals) -ethanol + CO2 (yeast/plants); both needed
What would be produced in anaerobic respiration in yeast cells ( Glucose --> Pyruvate --> ?)
Ethanol and CO2
What happens during the pathway of glycolysis?
Glucose is broken down into pyruvate
In cell respiration, what is the name of the process where glucose is broken down into pyruvate?
Glycolysis
What is formed from glucose during anaerobic cell respiration?
Lactate and ATP in cytoplasm
