structure of eukaryotic cells Flashcards
(18 cards)
nucleus
-nuclear envelope/double membrane that controls what enters and exits the cell as well as all reactions
-nuclear pores- rna
-nucleoplasm is jelly like and makes up bulk
-chromosomes which are protein bound dna
-contains dna and controls activity
-manufactures ribosomal rna and ribosomes through protein synthesis
nucleolus
-spherical region with the nucleoplasm
-manufactures ribosomal rna and ribosomes
rough endoplasmic reticulum
-3D system of sheet like membrane that spreads through the cytoplasm
-enclose network of tubules and sacs called cristae
-ribosomes on outer surface
-provides a large surface area for the synthesis of proteins and glycoproteins
-provides a pathway for the transport of proteins
smooth endoplasmic reticulum
-3D system of sheet like membrane that spreads through the cytoplasm
-enclose network of tubules and sacs called cristae
-lacks ribosomes on outer surface
-more tubular in appearance
-synthesises, stores and transports lipids and carbohydrates
golgi apparatus
-membranes to make cisternae
-hollow structures called vesicles
-forms glycoproteins
-produces secretory enzymes
-form lysosomes
-modification of proteins and packages them to be transported
ribosome
-cytoplasmic granules found in all cells
-80s found in eukaryotic cells
-70s found in prokaryotic cells, mitochondria and chloroplasts
-site of protein synthesis
lysosome
-formed when vesicles from golgi contain enzymes such as protease and lipase
-contains lysozymes
-they hydrolyse material ingested by phagocyte
-release enzymes to the outside of the cell in order to destroy material around the cell
-digest worn out organelles so that useful chemicals can be released
-completely break down cells after they die
vesicles
-a small fluid filled sac within the body
-formed during the secretion or uptake of transporting materials
-the move molecules
-secrete substances
-digest materials
-regulate cell pressure
cell surface membrane
-semi permeable lipid bilayer
-found in all cells
-acts as a differentially permeable layer which controls the entry and exit of chemicals
mitochondria
-rod shaped
-double membrane, cristae
-provides large SA for attachment of enzymes
-remainder proteins etc produce own enzymes in the matrix
-site of aerobic respiration
-produces ATP
-muscle and epithelial cells
chlorplast
-chloroplast envelope/double membrane
-grana made from thylakoids, large SA
-chlorophyll for photosynthesis
-stroma, fluid filled matrix, second stage of photosynthesis, possesses all enzymes
-where DNA and ribosomes synthesise proteins needed
plant cell wall
-microfibrils of cellulose embedded in a matrix
-thin layer with lamella in the middle, marks boundary between adjacent walls
-mechanical strength to prevent bursting during osmosis
- allows water to pass along it
centrioles
-paired barrel shaped organelles located in the cytoplasm of animal cells
-for cell division in animal cells
-formation of spindle fibres
-organises microtubals that serve as the cells skeletal system
vacuole
-fluid filled sac bound to a single membrane
-contains minerals, sugars, amino acids and pigments
-supports herbaceous plants by making them turgid
-sugars and AA act as temp food store
-pigments colour petals, attract pollenators
cytoplasm
-gelatinous liquid that fills the inside of a cell
-allows transport
-maintains cell shape and structure
-host to metabolic processes
bacterial capsule
-polysaccharide layer that lies outside the cel envelope
-can be the cause of various diseases
-protects bacterium form other cells and helps groups of bacteria to stick together for further protection
bacterial plasmid
-small circular DNA molecule found in bacteria and some other microscopic organisms
-processes the genes that may aid in the survival of bacteria in adverse conditions e.g. produces enzymes that break down antibiotics
bacterial cel wall
-peptidoglycan cell wall composed of dissacharides and amino acids
-physical barrier that excludes certain substances and protects against mechanical damage and osmotic lysis
