CELLS Flashcards
Cell theory
- Cells are the fundamental units of life
- All organisms are composed of cells
- All cells come from preexisting cells
Why cells are small
because high surface area to volume ratio is essential
we use microscopes to see the cells, as we have
magnification: increase the size of the cell
resolution: clarity of the magnification object
All living things are classified into three domains:
bacteria
archaea
eukarya
All living things are classified into three domains:
bacteria
archaea
eukarya
there are 2 types of cells
prokaryotic
eukaryotic
prokaryotic cells
no nucleus no membrane-bound organelles unicellular size: very small 0.2-2 miometer examples: bacteria and archaea
eukaryotic cells
DNA in the nuclear do have membrane bond wall can be unicellular or multicellular size: 10-100miometer examples : plant and animals
bacteria
- inclosed by plasma membrane
- the DNA is in the nucleoid
- ribosome: protein synthesis (RNA to protein)
- plasma: consist of cytosol
protective cell wall (plasma membrane)
- fluid
- made of phospholipids bilayer with protein and other molecules
- the outer surface of all cells
- rigid, bacteria cell walls contain (peptidoglycan)
- Some bacteria contain a slimy (capsule of polysaccharides) – protection, prevents attachment to other cells
some prokaryotic cells swim
..by (flagella), made of protein flagellin
*have single (pili), more pilus, hair like structure, help bacteria adherence to other cells
organells
- the parts in the eukaryotic cells
* each organelle have a specific role in cell function
similarities between animal and plant cell
nucleus Golgi apparatus lysosome cytoplasm cell wall rough/smooth endoplasmic reticulum ribosomes cell wall plasma membrane
organelles( contain membrane bound)
Nucleus – Mitochondrion – Endoplasmic reticulum(er) and Golgi apparatus – Lysosomes and vacuoles – Chloroplasts (some cells) –
Not organelles ( lack membranes)
ribosome
Cytoskeleton
Peroxisomes
ribosomes
protein synthesis
- in cytoplasm,
- attached to endoplasmic reticulum, *inside mitochondria and *chloroplasts.
The nucleus is surrounded by two membranes—
the nuclear envelope
outer and inner membrane
Nuclear pore -
*connect nucleus with the cytoplasm. *Allows nucleus to regulate
DNA combines with proteins to form chromatin in long,
*thin chromatin threads called (chromosomes)
Endoplasmic reticulum (ER)
*rough
have ribosomes
protein synthesis
*smooth
no ribosomes
lipid and steroids synthesis
Golgi apparatus
receive and identify proteins from RER/SER
EXP: some proteins become digestive enzymes , and they are backaged to type of vesicle called lysosome
lysosome
digestive enzyme from the Golgi apparatus
it combine with other vesicles from plasm membrane break it down releasing nutrients
mitochondria,
energy in fuel molecules is transformed to the bonds of energy-rich ATP
- have 2 membrane: inner membrane (folds inward to form cristae) and outer membrane
- matrix: contains enzymes and ribosomes.
- inter-membrane space: the space between inner membrane and the matrix
the Power plan of the cell is
mitochondrion
Chloroplasts
- photosynthesis: light energy converted to chemical energy bonds
- double membrane.
- Contain the green pigment chlorophyll
chloroplast (the green pigment)
- double membrane (inner/outer)
- stroma
- thylakoid
- granum ( stack, group of thylakoid)
Thylakoids
contain chlorophyll and other pigments that harvest light energy for photosynthesis.
Stroma—
fluid in which grana are suspended. The stroma contains DNA and ribosomes.
Peroxisomes
Collect and break down toxic byproducts of metabolism such as H2O2
plant cells have vacuole (functions)
- Storage, structure, reproduction, Digestion
The cytoskeleton has important functions:
- support and maintain cell shape
- moves organelle within the cell
- hold organelles in position
- Involved in cytoplasmic streaming (movements of the cytoplasm
- Interacts with extracellular structures to hold cell in place
