2.1 cell structure Flashcards
what is a cell membrane?
a partially permeable thin layer of protein and fat that surrounds the cell
what is the function of the cell membrane?
it controls what goes in and out of the cell
what is a cell wall?
a fully-permeable rigid wall made of cellulose that surrounds the plant cell
what keeps the cell wall rigid and how?
cellulose; it forms fibres which criss-cross over one another, creating a strong covering to the cell
what is the function of a cell wall?
to protect and support the cell
what is a cytoplasm?
a clear jelly made up of water and dissolved substances
what does cytoplasm contain?
organelles where metabolic reactions take place
what is a vacuole?
a space in the cell that is surrounded by the membrane
what does a vacuole contain?
a space in the cell that is surrounded by the membrane
what is the function of a vacuole?
it helps maintain pressure in the cells and keep it in shape
what is the vacuole in an animal cell called?
vesicles
what do chloroplasts contain?
chlorophyll and starch grains
what is the function of a chlorophyll?
it absorbs energy from sunlight to make food by photosynthesis
what is a nucleus?
the ‘control centre’ of the cell that contains the genetic information that carries the instructions that control the structure and activity of the cell
what is the function of a nucleus?
it helps make the right sorts of protein
characteristics of chromosomes
- made of DNA
- very long and thin
- when cell divides, it becomes short and thick
what is mitochondria?
the powerhouse of the cell
where is the mitochondria found?
found in almost all cells, except prokaryotes
what occurs in the mitochondria?
oxygen is used to release energy quickly from glucose by aerobic respiration–for fast movement
what kind of cells have lots of mitochondria?
cells that use a lot of energy
what is glycogen?
a reserved fuel and stored carbohydrates in animal cells
where is glycogen found?
in the cytoplasm
what is the function of the glycogen?
to be broken down to glucose to be used as fuel by the mitochondria in the liver cell, or transported in the blood to other cells that need it
what is a ribosome?
tiny organelles where protein synthesis takes place
what is the function of the ribosome?
it is where protein is made, by the junction of amino acids in a long chain
how is the junction of amino acids done?
it is done according to the instructions carried on the DNA, which specifies the sequence of amino acids that should be strung together to make a particular protein
