Cells and Organelles Flashcards
The bilateral of a cell membrane is a …… ?
Lipid
What is involved in signal transduction and transportation of substances to the cell?
Proteins
Cytoplasm
Contains network for support and organelles Cytoskeleton
Endoplasmic Reticulum
-rough
-smooth
no ribosomes
Made of flat sacs, canals, vesicles, involved in transportation of molecules within the cell and protein synthesis. Rough: covered by Ribosomes Smooth: no ribosomes, used for lipid synthesis
Ribosome
Attached to rough ER. Involved in protein synthesis Provides enzymes and support
Golgi apparatus
Packages/delivers proteins made by ribosomes Exocytosis: when they leave the cell
Mitochondria
Powerhouse of the cell Releases ATP Multi folded w/ enzymes
Lysosome
Enzyme filled sacs used for getting rid of or breaking down nutrients
Peroxisome
Houses enzymes for catalysis of biochemical rxns
Microtubules/microfilaments
Forms cytoskeleton Filaments are proteins bundled, tubules are bigger
Centrioles/centrosomes
Near Golgi body, no membrane, Transfer chromosomes during mitosis
Cilia/flagella
Cilia: short, ordered, precise movement
Flagella: long, random, singular
Vesicles
Vacuoles, used for transport of liquid or solids
Stores water and wastes, is very large in plant cells
Vacuoles
Nucleus
Control center of the cell that contains chromosomes made up of DNA
Nucleolus
Found in nucleus and makes ribosomes that migrate to the cytoplasm
made of RNA and protein, no membrane
Bacteria are an example of this type of cell
Prokaryotic
A cell with a nucleus and other organelles that can be seen
Eukaryotic
Cell membrane
Surrounds cellular contents Thin, flexible, Semi permeable Regulates movement of substances in/out of cell
Chromatin
Loosely coiled DNA and protein (chromosomes)
Passive mechanisms
- do not require cellular energy
Diffusion
movement of molecules from high to low pressure along a concentration gradient (the difference in concentrations).
Facilitated Diffusion
when molecules need “help” getting across the lipid bilayer cell membrane.
ex. insulin
Osmosis
when water moves from hi to lo concentration acouse a semipermeable membrane
water=solvent
and goes to areas where theres a need for more water molecules.
Osmotic Pressure
Pressure due to osmosis
3 types of osmotic pressure
- Isotonic
- Hypertonic
- Hypotonic
Isotonic
same pressure as body fluids inside and out.
Hypertonic
Higher pressure than body fluids due to lack of water outside of cell
(lots of solute outside cell, water will want to leave the cell to dilute the extracellular surroundings and cell will shrink)
Hypotonic
lower pressure than body fluids due to increased amounts of water molecules outside the cell.
(water will want to move in to the cell to dilute it , making the cell swell and break)
Filtration
forcing the movement of molecules.
Edema
when too much fluid is left in body tissues, this creates swelling
Active mechanisms
- mechanisms that require energy.
- ATP
movement of molecules from low to high pressure
(this is how transport differs from facilitated diffusion)
Ex. sodium and potassium pumps in the body. they require specific shaped protein to move it against the concentration gradient.
Endocytosis
Vesicles carry the molecule in to the cell
- Pinocytosis- taking in small liquids and vesicle wall disintegrates
- Phagocytosis- taking in solids via a vesicle, then lysosomes disolve the vesicle wall.
- receptor mediated endocytosis- specifically shaped proteins take in specific molecules (ligands)
Exocytosis
vesicles surround certain molecules, like hormones, and carry it to the cell membrane, where it is released outside of the cell.
The Cell Cycle
Part one of the cell cycle: Interphase
cell obtains nutrients, duplicates organelles and membranes,
DNA duplicates so two new cells can each have genetic instructions
G1-cell growth
S-Genetic material replicates
G2- more growth
Part Two of the Cell Cycle: Mitosis (PMAT)
Mitosis-produces division of the nucleus and its contents
Prophase
Chromosomes condense
Easily visible
Centrioles move to outer edge,
Spindle fibers form
Nuclear envelope dissapears
Metaphase
Chromosomes ine up along centrioles
(the chromosomes are lined up in the middle)
Anaphase
centromeres are pulled apart and individual chromosomes move in opposite directions.
Telophase
Chromosomes become chromatin
Nuclear envelope reforms around new nuclei
spindle fibers disassociate
Cytokinesis
division and “pinching’ off” pf the cytoplasm after nuclear division
begins in anaphase
New cell has ——–> same # of organelles
———> same copy of nucleus
Cell Differentiation
when cells specialize during development in order to perform different fxns
specific DNA is either repressed or expressed in each cell dpepending on need.
Unspecialized cell
Stem Cell
Cell death- Apoptosis
happens when time comes for cell to die. disintegrate
carrier protein
used to transport specific substances in and out of a cell.
Use of proteins
- inner: provide support
- outer (external): mark the cell, indentify or stick it to other cells
Signal transduction
molecules in the cell membrane send signals from out of the cell to the inside
ATP
adenosine triphosphate
Energy used in active mechanisms
