eukaryotic cell structure Flashcards
list organelles in eukaryotic animal cells
- cell membrane
- nucleus
- RER
- SER
- mitochondria
- lysosome
- golgi body
- vesicle
- centriole
structures in cell membrane
- phospholipid bilayer
- proteins
- cholesterol
function of cell membrane
- contains organelles
- selectively permeable to control entry and exit of materials
- protects cell from harmful chemicals
- takes part in metabolic processes
structures in nucleus
- chromosomes
- nucleoplasm
- nucleolus
- nuclear pores
- nuclear envelope
function of nucleus
- synthesis of ribosomes and RNA
- control centre for cell
- retaining genetic material in form of DNA and chromosomes consisting of protein-bound, linear DNA
function of nuclear pores
allows passage of large molecules such as messenger RNA
function of nuclear envelope
- controls entry and exit of materials
- contains reaction
function of nucleolus
- site of ribosome synthesis
size of nucleus
10-20 um in diameter
structures in mitochondria
- double membrane
- cristae
- matrix
function of mitochondria
- site of aerobic respiration (Krebs cycle/ oxidative phosphorylation pathway)
- production of ATP
function of matrix
contains proteins, ribosomes, DNA and enzymes
function of cristae
- extensions of inner membrane provide large surface area for enzymes and proteins in respiration
which type of cells contain high numbers of mitochondria?
cells involved in metabolic processes requiring lots of ATP
- muscle cells
- epithelial cells (absorbing substances from intestine by active transport)
what does ATP stand for and what is it?
- adenosine triphosphate
- nucleotide produced during respiration - transfer of energy
size/shape of mitochondria
1-10 um in length
rod-shaped
structures of golgi apparatus
- stacks of membranes forming cisternae with vesicles
function of golgi apparatus
- secretes carbs
- add carbs to proteins forming glycoproteins
- produces secretory enzymes
- transports lipids
- forms lysosomes
describe the strict sequence of lipids/proteins produced by ER passed through the golgi body
- modifies lipids by adding carbs
- labels them so they go to correct destination
- transported in vesicles which are pinched off the ends of the cisternae
- vesicles move to cell surface to fuse with membrane and release contents
in what type of cells is the golgi body well developed?
secretory cells such as epithelial cells lining intestine
what is a lysosome?
type of golgi vesicle releasing lysozymes (+ hydrolytic enzymes)
functions of a lysosome
- hydrolyse materials ingested by phagocytic cells
- release enzymes outside of cell to destroy materials around it (exocytosis)
- digest worn out organelles for reuse
- break down dead cells (autolysis)
structure of a ribosome
- small cytoplasmic granule (also found in RER)
- consists of a large and small subunuits
what are the two types of ribosomes?
80S -eukaryotic cells (25nm)
70S - prokaryotic cells, mitochondria and chloroplast (smaller)
function of ribosomes
protein synthesis
structure of RER (rough endoplasmic reticulum)
extensive network of membranes enclosing tubules and cisternae
- continuous with the nuclear membrane
functions of RER
- provide large SA for protein/glycoprotein synthesis
- pathway for transport of materials (proteins) throughout cell
structure of SER (smooth endoplasmic reticulum)
- no ribosomes on surface (smooth)
- more tubular in appearance
functions of SER
- synthesis, store and transport lipids
- synthesis, store and transport carbohydrates
list extra organelles in eukaryotic plant cells
- cell wall
- chloroplasts
- vacuole
structures of cell wall
- microfibrils of cellulose in a matrix and a thin layer called middle lamella
functions of cell wall
- provide mechanical strength for plant as a whole
- provide mechanical strength to prevent cell bursting due to osmosis
- controls movement of water
what is the cell wall of fungi made of?
polysaccharide - chitin (glycan +glycoproteins)
what is the cell wall of algae made of?
cellulose or glycoprotein or both
structure of vacuole
- fluid-filled sac bounded by single membrane (tonoplast)
- contains solution of mineral salts, sugars, amino acids, wastes and pigments (e.g. anthocyanin)
functions of vacuole
- support plants by making them turgid
- act as temporary food store (sugars/amino acids)
- pigments colour petals to attract pollinating insects
structures of chloroplasts
- chloroplast envelope
- grana
- stroma
function of chloroplast
carry out photosynthesis
function of chloroplast envelope
double plasma membrane which is selectively permeable to control entry and exit of materials
function/structure of grana
1st stage of photosynthesis (light absorption)
- stacks of thylakoids containing chlorophyll
function/structure of stroma
2nd stage of photosynthesis (synthesis of sugars)
- fluid-filled matrix containing other structures such as starch grains
how are chloroplasts adapted to their function for photosynthesis?
- granal membrane: large SA for attachment of chemicals which carry out 1st stage of photosynthesis (chlorophyll/ electron carriers/ enzymes
- stroma fluid - contains enzymes for synthesis of sugars in 2nd stage of photosynthesis
- DNA/ribosomes - manufacture proteins needed for photosynthesis
