Cell Biology Flashcards
What is the purpose of the ribosome?
The ribosomes are the site of the protein synthesis of a cell?
What is the function of the cell membrane?
The cell membrane controls the entry and exit of molecules
What is the purpose of the nucleus?
The nucleus controls and monitors the cells activities. It also possesses the genetic information of a cell.
What is the purpose of the mitochondria?
The mitochondria is the site of aerobic respiration. It produces ATP for the cell.
What is the purpose of the cytoplasm?
The cytoplasm is the site of all chemical reactions within the cell.
What is the purpose of the cell wall?
The cell wall supports and protects the cell’s shape.
What is the purpose of the chloroplasts?
The chloroplasts are the site for photosynthesis. It is only present in green plant cells to produce food.
What is the purpose of the vacuole?
The vacuole contains the cell sap.
What is the purpose of the flagellum?
The flagellum acts as a tail which helps the cell to move around.
What is the cell membrane made of?
The cell membrane is made up of phospholipid bilayers and protein molecules. The cell membrane is continuously moving.
What does selectively permeable mean?
Selectively permeable means that only certain molecules are able to pass through.
What does diffusion mean?
Diffusion is the movement of molecules from a high concentration to a low concentration down a concentration gradient. This is an example of passive transport.
Give an example of diffusion in animals.
Oxygen and glucose diffuse into the cells in your body for the process of respiration.
Give an example of diffusion in plants.
Carbon dioxide diffuses into the cell during the process of photosynthesis.
What does osmosis mean?
Osmosis is the movement of water from a high water concentration to a low water concentration through a selectively permeable membrane.
What happens to an animal cell in a hypotonic solution?
The water moves from a high concentration outside the cell to a low concentration inside the cell. This will cause the cell to burst.
What happens to an animal cell in a isotonic solution?
The cell in an isotonic solution will stay the same.
What will happen to an animal cell in a hypertonic solution?
Water moves from a phish water concentration inside the cell to a low water concentration outside the cell. This will enable the cell to shrink.
Hat happens to a plant cell in a hypotonic solution?
Water moves from a high water concentration outside the cell to a low water concentration inside the cell. This will cause the cell to become turgid.
What will happen to a plant cell placed in an isotonic solution?
The plant cell will stay the same in a isotonic solution. The cell be flaccid.
What will happen to a plant cell in a hypertonic solution?
The water will move from a high water concentration inside the cell to a low water concentration outside the cell. This will cause the cell to become plasmolysed.
What is active transport?
Active transport is the process by which dissolved molecules move across a cell membrane from a low to a high concentration. In active transport, particles move against the concentration gradient and therefore need an input of energy from the cell.
What is the name for the process of creating new cells?
Another name for cell division is mitosis.
Why is cell division necessary?
Cell division is required to create, replace and repair cells.
What is a matching set of chromosomes called?
A diploid
Describe the steps of mitosis.
- Chromosomes become visible.
- Chromosomes produce replicas and double up to form 2 identical chromatids joined by a centromere.
- Chromatids line up at equator and are contracted by spindle fibres which pull to opposing sides of the cell
- Separated chromatids are now called chromosomes. Cytoplasm begins to divide.
- Cell splits into two and two identical daughter cells are formed. Each cell contains identical genetic information.
Why is it important every new cell contains the same amount of chromosomes.
It is important so no genetic information is lost.
What is cell culture?
Cell culture refers to the removal of cells from an animal or plant and their subsequent growth in a favourable artificial environment.
What is DNA made up of?
DNA is made up of subunits called nucleotides which consists of a phosphate group, a deoxyribose sugar and a gene.
What are the complimentary pairs?
The complimentary pairs are : A&U T&A G&C C&G
What determines the amino acid?
The base sequence determines the type of amino acid that will be used in a protein
Describe the steps of protein synthesis.
- The DNA molecule inside the nucleus unzips which exposes the base pairs.
- mRNA nucleotides form complimentary base pairs with the DNA.
- The newly formed mRNA molecule moves out the nucleus to the ribosome.
- Another form of RNA delivers an amino acid to the order of the mRNA bases.
- Amino acids are joined together by peptide bonds. The protein is then packaged and released from the cell.
What are enzymes?
Enzymes are biological catalysts that speed up reactions without being used up itself.
What are enzymes made up of?
Enzymes are made up of proteins.
What is the lock and key theory?
Enzymes are specific. This means that only a certain enzyme will work with a certain substrate. This can be compared to a lock and key.
What is a degradation reaction?
A degradation reaction is one which breaks down molecules into smaller molecules.
What is a synthesis reaction?
A synthesis reaction is one in which small molecules are built up into larger molecules.
What does optimum mean?
Optimum means the conditions in which the enzyme works best in such as temperature and pH.
