y3.1: cells ⛓ Flashcards
what are animal cells organelles (structures)?
cell membrane
what are animal cells organelles (membraneous)?
- nucleus
- cytoplasm
- rough + smooth endoplasmic reticulum
- Golgi apparatus
- vesicles
- mitochondria
- lysosome
- vacuole (smol)
what are animals cell organelles (non-membraneous)?
- ribosome
- centriole
what are plant cells organelles (structures)?
- cell membrane
- cell wall
what are plant cell organelles (membraneous)?
- nucleus
- cytoplasm
- large central vacuole
- chloroplast
- rough + smooth endoplasmic reticulum
- Golgi apparatus
- vesicles
- mitochondrion
what are plant cell organelles (non-membraneous)?
ribosomes
cell wall function
provide mechanical support and turgidity for plant
describe the fluid mosaic model (cell membrane)
- cell membrane is a phospholipid bilayer
- phospholipids and proteins can move rapidly across the surface of the membrane (fluid)
- different protein molecules randomly scattered and embedded in the phospholipid bilayer (mosaic)
cell membrane function
- separates and protects cell from surrounding environment
- controls movement in and out of the cell
what is cytoplasmic streaming?
movement of cytoplasm within a plant or animal cell which aids in the transport of materials and organelles around the cell
nucleus function
contains hereditary material (DNA)
controls the activities of the cell
contain nucleolus which is site of ribosome synthesis
smooth endoplasmic reticulum function
- lipid synthesis
- detoxification of drugs and poisons
- storage and release of calcium ions
rough endoplasmic reticulum function
protein synthesis
Golgi apparatus function
chemically modifies and packages substances for secretion using vesicles
protein synthesis to secretion process
1) transport vesicles containing substances synthesised by the ribosomes in the ER are pinched off the ER
2) transport vesicles fuse and release their substances into the Golgi apparatus
3) the substances are chemically modified and packaged in the Golgi apparatus
4) secretory vesicles containing these modified substances are pinched off the Golgi apparatus
5) secretory vesicles move towards and fuse with the cell membrane, releasing their substances via exocytosis
lysosome function
small, spherical vesicles containing hydrolytic enzymes
- to digest materials made in the cell or taken from the outside by phagocytosis
- to digest worn-out organelles in the cell (autophagy)
mitochondrion function
involved in aerobic respiration which results in the formation of ATP
chloroplast function
sites of photosynthesis (contains chlorophyll)
- light-dependent: thylakoid
- light-independent: stroma
(move through the cell by cytoplasmic streaming)
animal vacuoles function
relatively smaller and more numerous than plant vesicles and exist temporarily
- food vacuoles formed by phagocytosis
- storage vacuoles for food, water, nutrients, waste
plant vacuoles structure + functions
large, permanent, central vacuole surrounded by tonoplast, filled with cell sap
- storage of nutrients and ions
- disposal sites for metabolic by-products
- contains pigments
ribosomes functions
can be free or bound to RER
- protein synthesis
- free: function within the cytosol
- bound: secretion
centrioles function
occur in pairs
- cell division
structure of plant cell vs animal cell
PLANT VS ANIMAL
cell wall: present vs absent
chloroplasts: present vs absent
centrioles: absent vs present
vacuole: single, large, permanent, central vacuole vs small, numerous, temporary vacuoles
what is cell differentiation / specialisation?
differentiation is the process by which a cell is specialised for a specific function (eg RBC and root hair cell)
what is root hair cell structural adaptation to function?
1) presence of long narrow extension
- increases the surface area to volume ratio => increases rate of diffusion of mineral salts + rate of osmosis => increases rate of absorption of water and mineral salts
what are red blood cell structural adaptations to function?
1) absence of nucleus
- allows more haemoglobin to be packed into cells
2) presence of haemoglobin
- combines reversibly with oxygen
3) biconcave shape
- increases surface area to volume ratio to increase rate of diffusion of gases in and out the cell
what is a tissue?
a group of similar cells which work together to carry out a particular function
- simple: one type of cell
- complex: several types of cells (eg xylem tissue)
what is an organ?
different tissues working together to carry out a particular function
what is an organ system?
different organs working together to carry out a particular function
what is an organism?
several organ systems, each with its own function to carry out
