2.1 - cell structure * Flashcards
1
Q
plasma membrane?
A
- on surface of animal cells + between cell membrane and cell wall in plant cells and prokaryotes.
- made of lipids and proteins mainly.
- regulates movement of substances in and out of cell.
- has receptor molecules to respond to chemicals.
2
Q
cell wall?
A
made of cellulose + supports plant cells
3
Q
nucleus?
A
- surrounded by nuclear envelope (double membrane) which has pores
- contains chromatin (DNA + proteins) + nucleolus
- controls cells activities, DNA contains instructions to make proteins, pores allow substances (eg: RNA) to move between nucleus and cytoplasm, nucleolus makes ribosomes
4
Q
lysosome?
A
- round, membrane surrounded, no clear structure
- contains digestive enzymes which digest invading cells or break down worn out cell components
5
Q
ribosome?
A
- has small and large subsections
- very small, site of protein synthesis
- either floats around cytoplasm or attached to RER
- made of proteins and RNA, not membrane bound
6
Q
rough endoplasmic reticulum (RER)?
A
- system of membranes enclosing a fluid-filled space + surface is
covered with ribosomes - folds and processes proteins
7
Q
smooth endoplasmic reticulum (SER)?
A
- no ribosomes
- synthesises + processes lipids
8
Q
vesicle?
A
- small membrane-bound, fluid-filled sac in cytoplasm
- transports substances in/out cell via plasma membrane
9
Q
golgi apparatus?
A
- group of membrane-bound, fluid-filled, flattened sacs, vesicles at edge of sacs
- processes and packages new lipids and proteins + males lysosomes
10
Q
mitochondrion?
A
- oval shaped
- double membrane - inner one is folded to form cristae structures - inside is matrix which contains enzymes involved in respiration
- site of aerobic respiration + produces ATP
11
Q
chloroplast?
A
- small + flat
- double membrane - membrane stacked up to form grana - which are linked together by lamellae (thin pieces of thylakoid membrane)
- site of photosynthesis
12
Q
centriole?
A
- small hollow cylinders - made of microtubules (tiny protein cylinders)
- involved with the separation of chromosomes during cell division
13
Q
cilia?
A
- small hair-like structures
- have an outer membrane and ring of nine pairs of protein microtubules inside with two microtubules in middle
- microtubules allow cilia to move
- this movement used by cell to move substances along cell surface
14
Q
flagellum?
A
- stick out from the cell surface and surrounded by plasma membrane
- two microtubules in the centre and nine pairs around the edge
- microtubules contract to make flagellum move
- flagella used to propel cells forward
15
Q
plant vacuole?
A
- single sac filled with fluid of salts, sugars + amino acids
- surrounded by membrane called tonoplast
- store water, nutrients + waste materials until cell can get rid of them
16
Q
light microscope?
A
- poor resolution due to long wavelength of light
- living samples can be examined + a colour image is obtained
17
Q
cytoskeleton?
A
- network of fibres found within cytoplasm all over cell
- consists of microfilaments, microtubules + intermediate fibres
- provides mechanical strength + maintains shape and stability
- microfilaments responsible for cell movement
- microtubules responsible for creating scaffold like structure