YEAR 9 Cells And Transport In Cells Flashcards
List the features of an animal cell:
Cell membrane
Nucleus
Mitochondria
Ribosome
Cytoplasm
Describe the cell membrane
Semi permeable, controls the movement of substances in and out of the cell.
Describe the nucleus
Contains genetic material, controls the activities of the cell and codes fro proteins.
Describe the mitochondria
Site of respiration where energy is released for the cell to function.
Describe the ribosome
Site of protein synthesis, mRNA is translated to an amino chain here.
Describe the cytoplasm
Site of chemical reactions in the cell, gel like substance containing enzymes to catalyse the reactions.
List the features of a plant cell:
Permanent vacuole
Cell wall
Chloroplasts
Describe the permanent vacuole
Contains cell sap, keeps the cell turgid, contains sugars and salts in the solution.
Describe the cell wall
Made of cellulose, supports and strengthens the cell
Describe the chloroplasts
Site of photosynthesis, contains chlorophyll, and absorbs light energy
List the features of a bacterial cell
Bacterial DNA
Cell Wall
Flagella
Describe bacterial DNA
Not in the nucleus, floats in the cytoplasm
Describe the cell wall in bacterial cells
Not made of cellulose
Describe the flagella
Has a whip like tail, allows the bacterial cells to move
Compare the size of the three cells:
Bacterial cells are much smaller than plant and animal cells
Describe the functions of an egg cell
Fertilised by a sperm, nutrients in the cytoplasm, haploid nucleus and changes in the cell membrane after fertilisation.
Describe the functions of a sperm cell
To fertilise an egg, streamlines with a long tail, known as an acrosome containing enzymes and a large number of mitochondria, and has a haploid nucleus.
Describe the functions of a ciliates epithelial cell
Pushes and moves mucus, thin layer of moving hairs on the surface of the cells called cilia.
Describe diffusion
The movement of particles in a solution or gas from an area of higher concentration to an area of lower concentration, resulting in particles spreading out evenly.
Describe osmosis
Like diffusion, but it specifically refers to the movement of water molecules across a semi permeable membrane from an area of lower solute concentration to an area of higher solute concentration.
Describe active transport
The movement of particles from a dilute solution to a more concentrated solution.
State the energy requirement of each of the forms of transport
Diffusion - no energy required
Osmosis - no energy required
Active transport - energy required as it is going against the concentration gradient
Give an example of diffusion
02 and CO2 in gas exchange, urea in kidneys. Factors that affect the rate of concentration, temperature and surface area.
Give an example of osmosis
Plants absorb water from the soil by osmosis through their root hair cells. Plants use the water for several vital processes including photosynthesis and transporting minerals.
Give an example of active transport
Movement of mineral ions into roots of plants and the movement of glucose into the small intestine.
State the rule of diffusion
The greater the difference in concentrations the faster the rate of diffusion.
State the osmosis equation
Percentage change in mass = (final mass - initial mass) / initial mass x 100
