Group1
What is the role of the nervous system?
The nervous system's role is to coordinate and regulate body functions in response to changes in the environment.
True or False?
Information passes along neurones in the form of electrical impulses.
True.
Information is passed along neurones and between the different parts of the nervous system in the form of electrical impulses.
What happens after a reaction has occurred in the active site of an enzyme?
After the reaction has occurred the products leave the enzyme's active site and the enzyme is free to take up another substrate.
Name the largest organelle present within animal cells.
The largest organelle within animal cells is the nucleus.
True or False?
The gel-like fluid present inside both plant and animal cells is the chloroplast.
False.
The gel-like fluid present in plant and animal cells is the cytoplasm. Chloroplasts are organelles found in plant cells.
Define the term enzyme.
An enzyme is a protein that acts as a biological catalyst to speed up the rate of a chemical reaction.
True or False?
Enzymes are necessary for all living organisms.
True.
Enzymes are necessary for all living organisms to maintain reaction speeds at a rate that can sustain life.
Define the term optimum temperature.
The optimum temperature is the temperature at which an enzyme works fastest.
Name the structures present in plant cells that are not present in animal cells.
Plant cells have the following structures that are not present in animal cells:
cell wall
chloroplasts
permanent vacuole
True or False?
The role of the nucleus is to release energy for the cell.
False.
The role of the nucleus is to store genetic information in the form of DNA. Energy is released by the mitochondria.
What does a catalyst do?
A catalyst speeds up the rate of a chemical reaction without being used up or changed in the reaction.
True or False?
Enzymes are changed or used up in the reactions they catalyse.
False.
Enzymes are not changed or used up in the reactions they catalyse; they can be recycled and used in further reactions.
Define the term denatured.
When an enzyme is denatured its active site changes shape and can no longer bind to its specific substrate. This results in a loss of enzyme function.
Name three organelles found within animal cells.
Organelles present within animal cells are:
nucleus
mitochondria
ribosomes
Note that structures such as the cell membrane and cytoplasm are not organelles, so are not acceptable answers here.
What is the function of the cell membrane?
The cell membrane controls the passage of substances in and out of the cell.
Define the term substrate.
A substrate is the reactant of an enzyme-catalysed reaction.
True or False?
In a practical that investigates the effect of temperature on rate of reaction in amylase, the iodine solution will stop turning blue-black fastest at the optimum temperature.
True.
In a practical that investigates the effect of temperature on rate of reaction in amylase, the iodine solution will stop turning blue-black fastest at the optimum temperature; this is because the enzyme is working at its fastest rate breaking down the starch to sugar.
In a practical that investigates the effect of temperature on rate of reaction in enzymes, what happens to the rate at low temperatures?
In a practical that investigates the effect of temperature on rate of reaction, the rate of reaction will be slow at low temperatures. This is due to low kinetic energy.
What is the smallest organelle present in both plant and animal cells?
Ribosomes are the smallest organelle; they are present in both plant and animal cells.
True or False?
Muscle cells are likely to contain more mitochondria than skin cells.
True.
Muscle cells are likely to contain more mitochondria than skin cells. This is because they are more metabolically active, so will need more energy from respiration, the process that occurs inside mitochondria.
State the meaning of the term active site.
The active site is the region on an enzyme where a specific substrate attaches for the reaction to be catalysed.
True or False?
Ribosomes are present in both plant and animal cells.
True.
Ribosomes are present in plant and animal cells. They are the site of protein synthesis.
What separates cells from their surrounding environment?
The cell membrane separates cells from their surrounding environment.
What is the role of cell cytoplasm?
Cytoplasm is the site of chemical reactions inside cells.
What is the function of chloroplasts within plant cells?
Chloroplasts absorb light energy during the process of photosynthesis.