Cell Biology - 1.1, 1.2, 1.3 Flashcards
Look at diagrams in jotter for cell ultrastructure.
Revise plant, animal, fungal, bacterial
What is the function of the cell wall?
Outer layer of plant, fungal and bacterial cells, helps support the cell.
What is the function of the mitochondrian?
Main site of ATP production in aerobic respiration in animal, plant and fungal cells.
What is the function of a chloroplast?
Makes carbohydrates on green plant cells, using light energy in the process of photosynthethis.
What is the function of the cell membrane?
A selectively permeable membrane that controls the entry and exit of substances such as oxygen, carbon dioxide, glucose and waste to and from cells.
What is function of the cytoplasm?
Stores the cell organelles and site of chemical reactions.
What is function of the vacuole?
Membrane-bound sacs that store a solution of water, salts and sugars and helps support plant and fungal cells.
What is the function of the nucleus?
Contains genetic information (DNA) in animal, plant, and fungal cells to control cell activities.
What is the function of a ribosome?
Site of protein synthesis in cells.
What is the function of a plasmid?
A small ring of genetic material found in bacterial cells.
What cell structures does a plant cell have?
cell wall, mitochondrion, chloroplast, cell membrane, cytoplasm, vacuole, nucleus, ribosome.
What cell structures does an animal cell have?
mitochondrion, cell membrane, cytoplasm, nucleus, ribosome.
What cell structures does a fungal cell have?
cell wall, mitochondrion, cell membrane, cytoplasm, vacuole, nucleus, ribosome.
What cell structures does a bacterial cell have?
cell wall, cell membrane, ribosome and plasmid, cytoplasm
What material is the cell wall made from in plant cells?
cellulose
What is the difference between a plant and a fungal cell?
their cell walls are made of different materials (fungal cell is made of chitin) Only the plant cell has chloroplasts
What are the similarities between a plant and a fungal cell?
They both have cell wall, mitochondrion, cell membrane, cytoplasm, vacuole, nucleus, ribosome.
What is the difference between a plant and a bacterial cell?
Bacterial cells are made from peptidoglycan.
What does the cell membrane consist of?
Phospholipids and protein
What is the cell membrane?
selectively permeable
What do different concentrations exist between?
cells and their environment.
What does passive transport occur down?
a concentration gradient
What does passive transport not require?
energy
What are some examples of passive transport?
diffusion and osmosis
What is diffusion?
the movement of molecules down a concentration gradient from a higher to a lower concentration.
Explain the diffusion of oxygen.
The air that is breathed into the lungs is high in oxygen. The blood that has been brought to the lungs is low in oxygen the oxygen will then move from a high concentration in the lungs to a low concentration in the surrounding blood.
Explain the diffusion of carbon dioxide.
The blood that arrives at the lungs is high in the waste substance carbon dioxide. The air that is breathed in is low in carbon dioxide. Therefore the high concentration of carbon dioxide in the lungs and it will then be breathed out to a lower concetration.
Explain the diffusion of glucose.
the glucose moves from high concentration in the small intestine to a lower concentration in the blood by diffusion.
What is osmosis?
Osmosis is the movement of water molecules from a higher water concentration to a lower water concentration through a selectively permeable membrane.
If a red blood cell (animal cell) is placed in a solution that has a higher water concentration than their cytoplasm what will happen?
The cell will gain water and eventually burst
If a red blood cell (animal cell) is placed in a solution that has a lower water concentration than their cytoplasm what will happen?
The cell will lose water and shrink
What can plant cells become as a result of osmosis?
they can become turgid or plasmolysed
If a plant cell is placed in a solution that has a higher water concentration than the inside of the cell what will happen?
Water will move into the cell and cause the cell to swell and become turgid.
If a plant cell is placed in a solution that has a lower water concentration than the inside of the cell what will happen?
Water will move out of the cell and cause the cell to shrink and become plasmolysed.
If a plant cell is placed in a solution that has the same water concentration than the inside of the cell what will happen?
The same amount of water will move into the cell as out of the cell. This will cause the cell to stay the same.
Why does a plant cell not burst when it takes in water by osmosis?
The cell wall stop the cell from bursting (this is why the animal cell bursts, because it doesn’t have a cell wall)
In osmosis what does water move through?
a selectively-permeable membrane
What is a concentration gradient?
the difference in concentration between two solutions of the same substance.
What does passive transport involve?
The overall movement of molecules from an area of high concentration to an area of low concentration. This process does not require energy
What is active transport?
the movement of molecules from an area of low concentration to an area of high concentration against the concentration gradient. (requires energy)
What is active transport energy supplied by?
ATP
What is active transport energy carried out by?
proteins in the cell membrane called protein pumps.
What does active transport require energy for?
membrane proteins to move molecules and ions against the concentration gradient.
What is the structure of DNA?
a double-stranded helix held by complementary base pairs.
What does DNA carry?
the genetic information for making proteins.
What are the four bases of DNA called?
adenine, cytosine, guanine and thymine (A, C, G and T)
In the double strand what bases are paired with each other?
A is always paired with T and C is always paired with G.
What is the sequence of bases along a strand called?
the genetic code
What does the base sequence determine?
amino acid sequence in proteins.
What is a gene?
a section of DNA on a chromosome that codes for a protein.
What is messenger RNA?
is a molecule that carries a complementary copy of the genetic code from the DNA, in the nucleus, to a ribosome, where the protein is assembled from amino acids.
What is passive transport and what do we need it for?
passive transport is the overall movement of molecules from an area of high concentration to and area of low concentration, it does not require energy. We need passive transport so that oxygen and glucose can enter the body and so that carbon dioxide and waste can leave.
