what is the structure of the nucleus?
- surrounded by 2 membranes called a nuclear envelope
- envelope contains nuclear pores
- nucleus contains linear DNA
- darker staining area called a nucleolus
what is the function of the nucleus?
produces mRNA, tRNA and ribosome RNA- the pores allow them to leave the nucleus and into the cell
contains genetic material and codes
what is the structure of the ribosome?
free in the cytoplasm or attatched to the RER
made of RNA and proteins
80s in eukaryotic, 70s in prokaryotic
what is the function of the ribosome?
site of protein synthesis
what is the structure of the mitochondria?
2 membranes (envelope)
1-10 um in length
inner membrane is folded (cristae) for a larger SA
matrix contains lipids, ribosome and dna so it can produce its own proteins
what is the function of the mitochondria?
aerobic respiration (ATP)
what is the structure of the cell wall (plant cells) ?
rigid- made of cellulose embedded in a matrix
middle lamella thin layer boundry
algae ( cellulose) fungi (chilin)
what is the function of a cell wall (plant cells) ?
-provides mechanical strength
-prevents cell from bursting when water moves in
-freely permeable
what is the structure of the vacuole?
- surrounded by a membrane called a tonoplast
- vacuole is fluid filled
what is the function of the vacuole?
- tonoplast controls the exchange of material between the vacuole+ cytoplasm
- make cell turgid for support
what is the structure of the chloroplast?
- surrounded by 2 layers of membrane (envelope)
- stroma (jelly like substance)
- membranes forming flattening sacks called thylakoid membranes- stacks=grana
- small starch grains+ lipids in the stroma
what is the function of the chloroplast?
photosynthesis
what is the structure of the lysosome?
- have a single membrane
- contain hydrolyctic (digestive) enzymes- protease, lipase and lysozymes
- size up to 1um
what is the function of the lysosome?
- digest old cell organelles
- hydrolyse material ingested by phagocytic cells
- release enzymes to the outside of the cell
what is the structure of the golgi apparatus?
- formed in vesicles which bud off the rough ER
- broken down at the other end to form golgi vesicles
what is the function of the golgi apparatus?
- molecules ( proteins and lipids) are processed and sorted into golgi vesicles for transport
- make lysosomes
what is the structure of the endoplastic reticulum?
membrane organelle
can have ribosomes attatched ( RER)
what is the function of the endoplastic reticulum?
RER- provides a large surface area for synthesis of proteins and glycoproteins- then transports them through the cell
makes golgi apparatus
SER- synthesises proteins, stores+ transports lipids and carbohydrates
what is the structure of the cell surface membrane?
7nm thick
plasma membrane
what is the function of the cell surface membrane?
partially permeable which controls exchange between the cell and the environment
what is the division of labour?
how proteins are made, packaged and transported throughout the cell
what are the steps for the division of labour?
1) DNA in the nucleus contain instructions to make proteins
2) Protein synthesis in the ribosome
3) Protein transported through RER
4) Protein molecules are pinched off in vesicles and are transported towards the golgi apparatus
5) Vesicles fuses with golgi apparatus
6) Golgi apparatus process and packages protein ready to release
7) Protein molecules are then pinched off in vesicles from ga and transported towards the plasma membrane
8) Vesicle fuse with plasma membrane
9) Protein leaves cell by exocytosis
what is the function of a sperm cell?
delivers genetic material to the female gamete
what are the adaptations of a sperm cell?
-haploid genome to combine with female dna
- many mitochondria for energy
-undulipodium acts as a tail to propell cell
- acrosome in the head is filled with digestive enzymes to break down layer of the egg
