2.1 CELL STRUCTURE Flashcards
What is a eukaryotic cell?
The DNA has a nucleus, and it has membrane bound organelles.
What is a prokaryotic cell?
The DNA is free in the cytoplasm and it has no membrane bound organelles.
What is the structure of the nucleus?
- Nuclear envelope membrane.
- Nuclear pores, controls what come in and out of nucleus.
- Nucleoplasm to make rRNA.
What is the function of the nucleus?
- Site of protein synthesis.
- Contains genetic information.
- Makes ribosomes.
What is the structure of the mitochondria?
- Double layer membrane controlling what enters and leaves.
- Membranes folded over to form cristae that increase SA.
- Matrix of biological molecules.
What is the function of mitochondria?
- Site of aerobic respiration.
- Produces ATP for respiration.
What is the structure of the chloroplast?
- Double membrane to control entry and exit.
- Have discs of membrane called thylakoids.
- Many thylakoids together form the grana to increase SA.
- Stroma of biological molecules (matrix).
What is the function of chloroplasts?
- Site of photosynthesis
- Stroma provides glucose for photosynthesis.
What is the structure of the Golgi apparatus?
Stacks of membranes with vesicles on them. (cisternae)
What is the function of the Golgi apparatus?
- Modifies and packages proteins.
- Forms lysosomes.
- Makes glycoproteins.
- Lipids come here to get modified, bind to vesicles, and the leave the apparatus.
What is the structure of a lysosome?
- Single layer membrane
- Simple sac filled with lysozyme, digestive enzymes.
What is the function of a lysosome?
- Breaks down cells after death.
- Releases digestive enzymes by exocytosis.
- Hydrolyses digested cell.
What is the structure of the endoplasmic reticulum?
- 3d sheets of membrane, forming the cisternae.
Rough: has ribosomes on the surface
What is the function of rough endoplasmic reticulum?
Site of protein-synthesis.
What is the function of smooth endoplasmic reticulum?
Site of lipid-synthesis
What is the structure of ribosomes?
Has two subunits, and is formed by the combination of rRNA and proteins.
What is the function of ribosomes?
Site of translation where:
Large sub-unit: holds the amino acid binding site.
Small sub-unit: holts the mRNA binding site.
What is the structure of the cell wall?
- Made up of polysaccharides
- Has a middle boundary lamallae to separate adjacent cell walls.
What is a plant cell wall made of?
Cellulose
What is a bacteria / fungi cell wall made of?
Murein
What is the function of the cell wall?
- Provides support to cell.
- Acts as a barrier to pathogens.
- Provides the apoplast pathway for the diffusion of water in plants.
What is the structure of the vacuole in plants?
Simple membrane containing cell sap.
What is the function of the vacuole in plants?
- Support the plant.
- Provides and stores sugars / amino acids / minerals / enzymes etc.
What is the function of plasmids in prokaryotes?
Carries DNA.