cells Flashcards
cell theory
All organisms are composed of cells (and products of cells)
All cells come from preexisting cells
The cell is the basic organisational unit of living things
what is an organelle?
a specialised structure in a cell.
what are enzymes?
a protein molecule that acts as a biological catalyst, speeding up reactions.
what is a biomolecule?
biological molecules, produced by cells that are used to build new organelles.
what are the types of cells and a description of each?
Prokaryotes: bacteria and archaea. Usually unicellular and are smaller and less complex than eukaryotic cells.
Eukaryotes: plants, animals, fungi and protists. Contain MBO.
what are common features cells? (4)
Plasma membrane
Cytoplasm
DNA
Ribosomes
what are prokaryotic cells? where cab they be found? what are some features? DNA? hairs?
Unicellular
Simple
Can be found in extreme environments
Small
No MBO or distinct nucleus
Cytoplasm: scattered ribosomes
single, circular DNA chromosome called genophore contained in the irregular shaped nucleiod
Nucleoid does not have a membrane
DNA is connected to the plasma membrane at the origin
Have many small rings of double stranded DNA called plasmids
Have a cell wall
Many have a capsule that protects from damage and dehydration (around cell wall)
Flagella
Pilus: hair like projections that transfer DNA between organisms and help with movement.
what are protists?
large group of single-celled organisms that cannot be classified as a plant, animal or fungus and have characteristics of all.
what are eukaryotic cells? what are some features?
Have a plasma membrane
Have internal membranes that make organelles
Cell compartmentalisation
what governs what organlles a eukaryotic cell has? are they the same in prokaryotes?
Presence depends on need of cell for their function
May have the same type of organelles as prokaryotes (flagella, ribosomes, cell wall) but they differ
nucleus- structure, function, plant/animal
structure:
Double membrane
Contains DNA
function:
Contains genetic information used for synthesis of protein
Directs activities of cell
p/a:
both
nucleolus: strucre, function, plant/animal
s:
Made of proteins and RNA
f:
Forms incomplete ribosomes
a/p:
both
rough endoplasmic reticulum: structure, function, p/a
s:
Membrane bound
composed of a network of membraneous tubules and sacs (cisternae)
Ribosomes bind to membrane
f:
Synthesis and processes proteins often by adding carbohydrates to proteins made by ribosomes to from glycoproteins
a/p:
both
ribosomes: s, f, a/p
s:
“Made of proteins and ribosomal RNA
Free or bound to RER”
f:
“Translates messenger RNA into proteins
RER bound synthesis proteins for export “
p/a:
both
Golgi apparatus: s, f, p/a
s:
“Membrane bound
Stack of cistern that are disconnected “
f:
Processes and packages proteins into vesicles for export (except lysosomes which stay in the cell)
p/a:
both
lysosome: s, f, p/a
s:
“Membrane bound
Vesicle containing digestive enzymes”
f:
Digest waste and foreign material
p/a:
animal
smooth ER: s, f, p/a
s:
“Membrane bound
System of cisternae “
f:
Synthesis of lipids
p/a:
both
mitochondrion: s, f, p/a
s:
“Double membrane (inner is highly folded)
Contains DNA”
f:
Releases energy from organic compounds
p/a:
both
chloroplast: s, f, p/a
s:
“Double membrane
Contains thylakoid sacs (disk-shaped membrane sacs)
Has DNA”
f:
Uses light, carbon dioxide and water to make glucose
p/a:
plants
centriole
s:
Uses light, carbon dioxide and water to make glucose
f:
Uses light, carbon dioxide and water to make glucose
p/a:
Sometimes on plants and always in animals
cilia and flagella: s, f, p/a
s:
“External structures
Composed of microtubules “
f:
Involved in movement of the cell or things around the cell
p/a:
both
vacuoles: s, f, p/a
s:
“Membrane bound
Vesicles “
f:
“Storage
Structure in plants “
p/a:
In plants and small or absent in animals
plastids other than chloroplasts: s, f, p/a
s:
“Small
Double membrane
DNA”
f:
Synthesis and storage of diverse organic compounds
p/a:
plants
peroxisomes: s, f, p/a
s:
“Small
Double membrane
DNA”
f:
involved in metabolic reactions involving oxidation of harmful materials
p/a:
both
cell wall (not organelle): s, f, p/a
s:
“External structure that surrounds plasma membrane
Made of cellulose (murein in bacteria)”
f:
Structural support and protection
p/a:
plants
cytoskeleton : s, f, p/a
s:
3D internal support and transport network that fills the cytoplasm of eukaryotes
f:
Internal support and transport and stability through microfilaments, intermediate filaments and microtubules
p/a:
plants
