Exam Questions Flashcards
In what part of the cell does glycolysis occur?
Cytosol
Name the end product if glycolysis.
Pyruvic acid
Comment on the amount of energy produced as a result of glycolysis.
Small amount of energy produced in the form 2 ATP per glucose molecule
Some cells contain large numbers of mitochondria. What does this indicate?
It is very active
Suggest one type of cell that you would expect to have few mitochondria present.
Fat cells
Suggest an advantage to the cell of using ATP as an energy source, instead of breaking down a sugar molecule Evey time energy is needed.
4 possible answers
ATP releases energy in suitable quantities
ATP is immediately available
ATP can be recycled easily
ATP is easily released
Name the nitrogenous base and the sugar present in ATP
Nitrogenous base in ATP = adenine
Sugar is ATP = ribose
Give a balanced chemical equation to summarize the process of aerobic respiration.
C6H12O6 + 6O2 -> 6H2O + 6CO2
Name the storage polysaccharide in humans from which glucose is produced.
Glycogen
Give one major storage location if glycogen in the body.
Liver or muscle
What happens to pyruvate molecules that prepare them for the Krebs Cycle?
They lose a carbon (C3 becomes C2) to become acetyl CoA (C2)
Name three products of the Krebs Cycle
ATP
NADH
CO2
Describe the fate of CO2 after it has left the Krebs Cycle
Released into the atmosphere or is used in photosynthesis
What is the final electron acceptor in aerobic respiration?
Oxygen
True or false?
Aerobic respiration occurs entirely in the cytosol?
False
True or false?
Glycolysis is an anaerobic process
True
True or false?
None of the energy released in respiration is lost as best.
False
True or false?
In respiration, all of the ATP molecules are produced in the Krebs Cycle
False
True or false?
ADP requires an input of energy to produce ATP
True
True or false?
When glucose is fermented by yeast, ethanol and water are formed.
False
True or false?
Fermentation releases more energy than aerobic respiration.
False
Name the three carbon molecule that is an intermediate compound in both aerobic and anaerobic respiration.
Pyruvic acid
What name is given to the biochemical pathway by which pyruvic acid is produced?
Glycolysis
What is produced from pyruvic when oxygen is not present in (a) muscles (b) yeast
A = lactic acid is produced B = ethanol and carbon dioxide
What is stage 1 of aerobic respiration called?
Glycolysis
What is the location of glycolysis in yeast cells?
Cytosol
Name a compound with 6 carbon atoms
Glucose
Name a compound which has 3 carbon atoms
Pyruvic acid
Name a compound with 2 carbon atoms
Acetyl CoA
Give two functions of water in yeast cells
6 possible answers
Medium for chemical reactions Maintains constant temperature Maintains shape Transports materials Solvent Biochemical reactant
Suggest an advantage of using ATP as an energy store in cells
5 possible answers
High-energy molecule Easily broken down Easily re-formed Reusable Energy released easily
Name two processes requiring ATP that occur in cells.
Respiration
Photosynthesis
Name two substances other than carbon dioxide into which pyruvate may be broken down under anaerobic conditions in cells
Lactic acid
Ethanol
What is the name of the two-carbon compound into which pyruvate is broken down under aerobic conditions?
Acetyl
Briefly describe the fate under aerobic conditions of acetyl
Enters Krebs Cycle where is is broken down into CO2 and protons (H+)
Write a note on Krebs Cycle
5 points
Occurs in the second stage of aerobic respiration
Occurs in the mitochondria
Requires O2 (aerobic)
Produces energised electrons
Breaks down acetyl into CO2 and hydrogen ions (H+/protons)
Write a note on ADP
3 points
Adenosine diphosphate
Low energy molecule
ADP + P used to form ATP + water during respiration
Explain the term fermentation.
Another name for anaerobic respiration
Name an organisms used in industrial fermentation
Yeast
To which kingdom does yeast belong?
Fungi
Name a compound which is used as a carbon source in the fermentation of yeast
Glucose
Explain the term bioprocessing
The use of enzyme-controlled reactions to produce a product
Explain the term immobilised
Immobilised enzymes are enzymes that are attached, or fixed, to each other, or to an inert material
(immobilised is to be attached, or fixed, to each other, or to an inert material)
Give an advantage of using immobilised cells in bioprocessing.
Immobilised cells can be reused while free cells cannot, the process is therefore cheaper if immobilised cells are used as they do not need to be replaced
Name the compound from which immobilised beads are formed are formed in the laboratory
Alginate
Give the general name for the vessel used during bioprocessing
Bioreactor
Write a brief note on glycolysis
6 points
First stage of aerobic respiration Occurs in the cytosol of the cell It is anaerobic Process begins with glucose Produces pyruvate (C3) Released a low amount of energy
Write a brief note on acetyl co-enzyme A
5 points
It is formed from pyruvate It is a 2-carbon molecule Joins the Krebs Cycle Made in the mitochondria Made in stage 2 of aerobic respiration in the presence of oxygen
Write a note on ATP in relation to respiration
5 points
High energy molecule Stores energy Releases energy Formed from ADP + P Large ATP production in stage 2 of aerobic respiration
Write a note on the electron transport chain in relation to respiration
Oxidative phosphorylation Carries high energy electrons made Electrons come from NADH produced in Krebs Cycle Forms water Aerobic process
Give two differences other than location between stage 1 and 2 of respiration
Stage 1 is anaerobic while stage 2 is aerobic
Stage 1 produces a small amount of energy while stage 2 produces a large amount of energy
Where in the cell does stage 1 occur
Cytosol
What term is used to describe respiration in which only stage 1 occurs
Anaerobic/fermentation
Name a chemical end product of anaerobic respiration
Ethanol or lactic acid
What molecule stores the energy released by electrons in the electron transport chain
ATP
Where are the electrons transferred to at the end of the electron transport chain?
1/2 oxygen and 2H+ to produce water
What name is given to the first stage of respiration
Glycolysis
In what organelle does stage 2 of respiration take place in the presence of oxygen
Mitochondria
What is the name of the C2 molecule which pyruvate is broken down into in stage 2 of respiration
Acetyl
What is the name of the series of reactions acetyl passes into in the second stage of respiration.
Krebs cycle
What is the energy released by electrons in the electron transport chain used for?
To form ATP
What happens to the electrons at the end of the electron transport chain?
Combines with 2H+ and 1/2 O2 to form water
Write a balanced equation to represent aerobic respiration
C6H12O6 +6O2 -> 6CO2 + 6H2O
What is the cytosol
The cytoplasm minus organelles i.e. it is the liquid part of the cytoplasm
Does the first stage of respiration release a small or large amount of energy?
A small amount of energy
What is fermentation
Another name for anaerobic respiration
Where in the cell does the second stage of aerobic respiration take place?
Mitochondrion
Is oxygen required for the second stage of aerobic respiration?
Yes
Suggest a situation in which some cells in the human body may not be able to engage in the second stage of aerobic respiration.
Lack of oxygen due to exercise
For what is ATP abbreviated
Adenosine Triphosphate
What is the role of ATP in cells?
Stores energy
To what substance is glucose normally converted in the first stage of respiration
Pyruvic acid
Is oxygen required for the conversion of glucose to pyruvic acid?
No
Name a compound to which pyruvic acid may be converted to in the absence of oxygen
Lactic acid or ethanol
What molecule is released when pyruvic acid is converted to an acetyle group
CO2
Explain the role of ADP in relation to the small amount of energy released in glycolysis
Uses energy to combine with a phosphate to form ATP which stores and transports energy
