Cell Biology Flashcards
There are four types of cells, what are they?
Animal.
Plant.
Bacterial.
Fungal.
What are cells?
Cells are the basic units of all living organisms.
What are organelles?
The different parts of a cell.
What is the function of the cell wall?
Provides shape and structure.
What is the function of mitochondria?
Site of aerobic respiration.
What is the function of chloroplasts?
Site of photosynthesis.
What is the function of the cell membrane?
Controls movement of substances in and out of a cell.
What is the function of the cytoplasm?
Site of chemical reactions.
What is the function of the vacuole?
Storage for water, sugars and salts.
What is the function of the nucleus?
Controls cells activities and contains genetic information.
What is the function of a ribosome?
Site of protein synthesis.
What are the functions of plasmids?
Small circular DNA.
What organelles does a plant cell contain?
Cell wall, cytoplasm, cell membrane, vacuole, nucleus, ribosome, mitochondria, chloroplasts.
What organelles does a animal cell contain?
Cytoplasm, cell membrane, ribosome, nucleus, mitochondria.
What organelles does a fungal cell contain?
Mitochondria, ribosomes, cell membrane, nucleus, cytoplasm, vacuole, cell wall.
What organelles does a bacteria cell contain?
Cytoplasm, plasmids, cell wall, cell membrane, circular DNA, ribosomes, capsule.
What are some uses for fungi?
Recycling nutrients, plant growth, food, medicines, decomposing waste and food.
Cells walls in fungal, bacterial and plant cells are all structurally and chemical different. What is each cells wall made of?
Plant cell - cellulose
Fungal cell - chitin
Bacterial cell - peptidoglycan
Cells are viewed using what?
A microscope.
Stains must be added to view the part of a cell. What stain is used for plant cells?
Iodine solution.
What stain is added to see animal cells clearly?
Methylene blue.
Total magnification is calculated by…?
Eyepiece Lens x Objective Lens
Cells are too small to be measured in millimetres (mm). What are they measured in?
Micrometers (μm).
How do you calculate the average cell length?
Count how many cells going from one side to the other and divide by the diameter.
The structure of a cell membrane is described as what and why?
Described as a ‘fluid mosaic model’ because it is made of phospholipids and proteins.
What do the lipids allow the membrane to do?
To be able to move, they make the membrane fluid.
Some proteins have channels running through them to allow what?
To allow certain substances to pass into and out of the cell.
The cell membrane is described as what?
Selectively permeable.
The cell wall is described as what?
Fully permeable.
What is the concentration gradient?
The different conditions inside and outside a cell.
What is passive transport?
The movement of molecules from an area of high concentration to an area of low concentration, down a concentration gradient, through a selectively permeable membrane until it is evenly spread.
Does passive transport require energy?
No.
What is diffusion?
A type of passive transport which is important as it allows cells to gain raw materials for respiration and remove harmful waste products.
What is osmosis?
A specific type of passive transport which is the movement of water.
What is a hypotonic solution?
A solution where there is less solute and more water.
What is a hypertonic solution?
A solution where there is more solute and less water.
What is an isotonic solution?
A solution that has equal measures of solute and water.
What is the osmotic effect on a plant cell placed in a hypotonic solution?
Water goes into the cell.
Cell becomes turgid.
Cell will never burst because of cell was so will only bulge.
Cell gains weight.
What is the osmotic effect on a plant cell placed in a isotonic solution?
There is no water movement.
There is no weight change.
What is the osmotic effect on a plant cell placed in a hypertonic solution?
Water goes out of the cell.
Cell becomes flaccid or plasmolysed.
Everything gets pulled in with vacuole.
Cell loses weight.
What is the osmotic effect on an animal cell when placed in a hypotonic solution?
Water moves into the cell.
Cell bursts because of no cell wall.
What is the osmotic effect on an animal cell when placed in a isotonic solution?
There is no weight change.
There is no water movement.
What is hen osmotic effect on an animal cell when placed in a hypertonic solution?
Water moves out of the cell.
Cell loses weight.
Cell shrinks.
What is active transport?
The movement of molecules from an area of high concentration to an area of low concentration, against a concentration gradient, through a selectively permeable membrane until it’s evenly spread.
Does active transport require energy?
Yes.
Sodium and potassium move in and out of what cell by active transport?
A nerve cell.
What factor effect active transport?
Oxygen concentration.
Glucose concentration.
Temperature.
Sodium/potassium pumps are located in a nerve cell. Nerve cells must maintain what?
A higher concentration of sodium outside the cell and potassium inside the cell.
The sodium/potassium protein pump pumps sodium ions out of the cell and what ions into the cell.
Potassium ions.
Why do cells divide?
To form a complete copy of themselves or to produce more cells for growth and repair.