cell functions Flashcards
Centrioles
involved in cell division- (spindle formed from centrioles and chromosomes attach to this which motor proteins walk up the threads)
-pull chromosomes to opposite ends
-involved in the formation of cilia and undilipodia (centrioles line up and multiply beneath cell surface membrane and they are formed by microtubules sprouting from each centriole)
Cytoskeleton
-protein microfilament give support and mechanical strength, keeping cell’s shape stable and allowing cell movement
-microtubules: provide shape and support to cells and help organelles move through cytoplasm + form the track that motor proteins walk and drag organelles from one part of cell to another
-form the spindle before cell division
-microtubules
-immediate filament made of variety of proteins: anchor the nucleus within cytoplasm, extend between cells so cell signalling allowed and cells adhere to basement membrane
-basement membrane stabilises tissue
Cellulose cell wall
-strong and can prevent cells from bursting
Cell wall:
-provides strength and support
-maintains cell’s shape
-permeable to allow solutions to pass through
Fungi have cell walls containing chitin instead of cellulose.
Ribosomes
site of translation (protein synthesis) - reads instruction to assemble amino acids into protein
Smooth endoplasmic reticulum
Synthesises and processes lipids.
-contains enzymes that catalyse reactions involved in lipid metabolism
-involved in absorption, synthesis and transport of lipids
Golgi apparatus
Processes and packages new lipids and proteins and also makes lysosomes.
-proteins modified e.g by adding sugar (glycoproteins) or adding lipid molecules (lipoproteins)
-proteins packaged into vesicles to be stored in cell or moved to plasma membrane
Rough endoplasmic reticulum
Folds and processes proteins that have been made at the ribosomes
-the intracellular transport system
-provides large surface area for ribosomes to assemble amino acids into proteins
-vesicles pinches off and transported to the Golgi apparatus
Mitochondria
The site of aerobic respiration where ATP is produced
-self-replicating
-abundant in very active cells
Cilia and undulipodia
The microtubules allow the cilia to move and the movement is used by the cell to move substances along the cell surface
-only human cell to have an undulipodium is a spermatozoon- enables it to move
Chloroplast
Site of photosynthesis
stage 1: light trapped by chlorophyll to make ATP where energy is released in grana
H2O split to supply H+ ions
stage 2: when hydrogen reduces CO2, makes carbs in stroma using energy from ATP
Nucleus, nuclear envelope, nucleolus, nuclear pore
Controls the cell’s activities by controlling transcription of DNA (contains instructions to make proteins)
Nucleolus: makes ribosomes
Nuclear pore: helps transport substances between nucleus and cytoplasm
Nuclear envelope: a double membrane
Chromatin: made from DNA wound up around histone proteins
Lysosome
Keep powerful hydrolytic enzymes away from the rest of the cell.
Engulf old cell organelles and foreign matter, digest them and return the digested component to the cell for reuse
Vacuole
-only plant cells have a large permanent vacuole filled with water and solutes
Maintains stability as pushes against the cell wall when full (turgid) which supports the plant, especially in non-woody parts
