Zusammenfassung der Ressource
Eukaryotic Cells
- Nucleus
- > Contains hereditary material and
controls cell activity.
- > Nuclear envelope - double
membrane - controls entry & exit.
- > Nuclear pores - allow
passage of large
molecules.
- > Nucleoplasm - jelly-like material.
- > Chromosomes -
linear DNA.
- > Nucleolus - manufactures RNA.
- Mitochondria
- > Double membrane. Inner two membranes is cristae.
- > Cristae - large surface area for enzymes.
- > Matrix - controls reproduction of proteins.
- > Produce ATP, site of aerobic respiration.
- Ribosomes
- Site of protein-synthesis.
- > 80s - eukaryotic cells.
- > 70s - prokaryotic cells.
- Cell Wall
- > Cellulose - strong, stops cell from
bursting. To give mechanical strength to
the plant.
- Lysosomes
- Formed when vesicles produced by
Golgi contain proteases and lipases.
- > Hydrolyse material ingested by phagocytic cells.
- > Digest worn out organelles so that the useful
chemicals that they are made out of can be reused.
- > Completely break
down cells after they
have become inactive.
- Golgi Apparatus
- Modifies and labels proteins.
- > Add
carbohydrates
to proteins to
form
glycoproteins.
- > Produce secretary enzymes.
- > Transport, modify and
store lipids.
- > Form lysosomes.
- Vacuoles
- > Tonoplast - single membrane. Makes cells turgid.
Sugars and amino acids act as a temporary store.
Pigments may attract pollinating insects.
- Endoplasmic reticulum
- > RER: ribosomes, provide
large surface area for
protein-synthesis.
- > SER: no ribosomes, synthesise, store
and transport lipids. Synthesise, store
and transport carbohydrates.
- Chloroplasts
- > Carry out photosynthesis.
- > Chloroplast envelope - double membrane.
- > Grana - stacks of thylakoids (contain chlorophyll)
- > Stroma - second stage of
photosynthesis. Contains starch grains.