The Cell Flashcards
What does a human cell consist of?
- cytoplasm and nuceloplasm
- organelles
- nucleus
- cell membrane
What cell doesnt have a nucleus?
Red blood cells
Describe the structure of the cell membrane?
- 2 layers of phospholipids with protein and carbohydrate molecules embedded in them
- arranged with heads to outside and tails to inside
- selective barrier, regulates passage of substances
What is the protoplasm?
Transparent jelly like material which is the living substance of the cell
What are the 2 types of protoplasm?
- cytoplasm- inside the cell, outside nucleus
- nucleoplasm- protoplasm within the nucelus
What is the function of protoplasm?
- reproduction
- responds to stimuli
- chemical processes take place
Describe mitochondria?
Mitochondria are membraneous, sausage shaped organelles
What is the function of mictonchondria
Contains enzymes that synthesise ATP
What cells have the greatest number of mitochondria?
The most metabolically active cells have greatest number of mitochondria eg liver and muscle
Describe the composition of ribosomes
Tiny granules composed of ribosomal RNA & protein
What is the function of ribosomes
They synthesise proteins from amino acids, using mRNA as a template
Where are ribosomes found?
- The outer surface of nuclear envelope
- rough endoplasmic reticulum
What is endoplasmic reticulum?
An extensive series of interconnecting membraneous canals in the cytoplasm
What is the function of smooth endoplasmic reticulum?
- synthesises lipids and steroid hormones
- detoxifies some drugs and converts glycogen to glucose
What is the function of rough endoplasmic reticulum?
Its studded with ribosomes, site of protein synthesis
