cellular ultrastructure and function test Flashcards
(29 cards)
Define the term ‘cell’
A membrane bound microorganism that contains organelles. Humans are made up of lots of cells.
What is the function of the plasma membrane?
Controls what comes in and out of the cell.
What is the function of cytoplasm?
A watery matrix that allows the transport of molecules.
What is the function of nucleus?
Controls all the activity in the cell.
What organelle has the function ‘site of ribosome synthesis’?
Nucleolus.
What organelle has the function ‘site of aerobic respiration’?
Mitochondria.
What organelle has the function ‘system of membranes with ribosomes attached. Site of protein synthesis’?
RER.
What is the function of SER?
Synthesise carbohydrates and lipids.
What is the function of centrioles?
Take part in cell division, they from spindle fibres that move chromosomes during cell division.
What organelle has the function ‘ vesicles that contain hydrolytic enzymes - break down waste materials inside the cell’?
Lysosomes.
What is the function of Golgi apparatus?
Newly made proteins are modified and packaged into vesicles.
Name four intracellular membranes
Lipid, Phospholipid, Lysosome, Mitochondria, Cell membrane.
State two functions of the cell surface membrane.
- Controls what goes in and out of the cell
- Acts as an antigen
State the function of cholesterol in cell membranes.
Provides stability to the cell membranes - not to stiff and not to jelly like.
Explain why cell membranes are described as ‘partially permeable’.
The cell membrane is partially permeable because not all molecules can go through the membrane, only some molecules. For example, molecules such as hydrocarbons and oxygen can cross the membrane, but larger molecules such as glucose cannot.
Name one structure in a cell membrane that can act as an antigen?
Glycoproteins.
Describe the function of antigens in the body.
Antigens identify the cell as “self” and can signal other cells that it is “self”.
Which part of the phospholipid molecule is hydrophobic?
Fatty acid tails.
Which part of the phospholipid molecule is hydrophilic?
Phospholipid head.
Which part of the phospholipid molecule faces towards the cytoplasm?
Phosphate head.
Which part of the phospholipid molecule is non-polar?
Fatty acid tails.
What is the shape of chromosomes in prokaryotic cells?
Circular.
What is the shape of chromosomes in eukaryotic cells?
Linear.
What is the size of ribosomes in prokaryotic cells?
70s.
