cells (organelles) Flashcards
(19 cards)
Nucleus
Contains DNA which controls activity of cell by containing base sequence
has histone proteins referred to chromatin wound into chromosomes
Nucleolus
Region within nucleus where ribosomes are made
Nuclear envelope
Double membrane that surrounds nucleus
Contains pores which allow small molecules to pass onto cytoplasm but keep hefty chromosomes inside
RER
Extension of nuclear envelope
Coated with ribosomes
Facilitates proteins synthesis by providing large SA for ribosomes
Transports newly synthesised proteins to Golgi for modification
SER
Synthesises lipids
cholesterol and steroid hormones
Golgi apparatus
Made up of a group of fluid filled membrane bound flattened sacs surrounded by vesicles
Receives proteins from RER and lipids from SER
It modifies the proteins and lipids and repackages them into vesicles
Site of lysosome synthesis
Ribosome
Translation of RNA into proteins
Float freely in cytoplasm or on RER
Mitochondria
Site of ATP production during aerobic respiration
Self replicating
Contains a double membrane with folds called cristae which provides large SA for respiration
Lysosome
Phospholipid rings which contain digestive enzymes separate from rest of cytoplasm
Engulf and destroy old organelles or foreign material
Chloroplast
Site of photosynthesis
Enclosed in double membrane
has internal thylakoid membranes arranged in stacks to form grana linked by lamellae
Plasma membrane
Phospholipid bilayer with additional proteins to serve as carriers
Contains cholesterol to regulate membrane fluidity
Contains the cell contents and holds the cell together
Controls movement of substances in and out the cell
Centrioles
Bundles of microtubules which form spindle fibres during mitosis in order to pull sister chromatids apart
Important for the formation of cilia and flagella
Cell wall
Rigid structure
Cellulose in plants
chitin in fungi
murein in prokaryotes
Provides support to the cell
Flagella
tail-like structure which are made up of bundles of microtubules
microtubules contract to make the flagellum move and propel the cell forward
Cilia
finger-like projections found on the surface of some cells
contain bundles of microtubules which contract to make the cilia move
Vacuole
stores cell sap and may also store nutrients and proteins
helps to keep plant cells turgid
digest large molecules
Plasmodesmata
channels (threads of cytoplasm) found between plant cells that enable them to communicate
Prokaryotes vs Eukaryotes
pro
-no membrane bound
-single circular chromosome
-plasmid dna
-smaller ribosome (70s)
-smaller in general
-flagella made out of flagellin
Prokaryotes vs eukaryotes
Euk
-linear dna
-larger ribosomes (80s)
-flagella made of microtubules
