Cell Biology Flashcards
All cells have too
- expel waist and bring in nutrients
- keep internal environment different then external
- Make proteins
- Divide and replicated
What are some characteristics of the plasma membrane
- selective barrier: allows important materials in but it others
- general structure: double layer of phospholipids
- Contributions from internal membrane system
- connections to cytoskeleton
What are integral proteins?
Wishing the bilayer of a cell, non polar R groups interact with the fatty acids in the hydrophobic regions
What are peripheral proteins?
Attached to the surface, joining cells and recognition of self and non self
What are he functions of enzymes?
Catalyze reactions
Binding sites exposed to accept substrates
What are the functions of transports
- move solutes, other molecules
- hydrophilic channels or shuttles
- some use atp
How often do phospholipids move side to side vs up and down?
Side to side - 10^7 per second
Up down once a month
How does cholesterol stabilize membrane fluidity?
Site in between phospholipids and reduces movement (prevents too much fluidity) and prevents tight packing ( prevents to much solidity)
Which fatty acid causes a membrane to be more fluid/ not solid
Unsaturated - more fluid
Saturated - more solid
Cell membrane is permeable to what?
Non polar molecules and opposite
What is the size of a cell and organelles
Cell 1-100um
Organelles ~1 um
As volume decreases what happens to size in a cell
Size increases
What are Protists
Unicellular eukaryotes the first eukaryotes to evolve
From oldest to newest name the major things that happened for development of life on earth
- prokaryotes
- atmospheric oxygen
- single called eukaryotes
- multicellular eukaryotes
- animals
- colonization of land
What cells evolved first and when
Prokaryotic cells 3.5 billion years ago
What caused the oxygen revolution?
Cell membranes specialized for photosynthesis in some of the first cells which produced oxygen and caused some cells to go extinct that couldn’t handle the oxygen
What is the cell membrane composed of?
Phospholipid bilayer (fatty acids and polar heads that interact with each other (yellow and purple model))
How do cells react to temperature change?
Change Their phosphlypid composition- if temperate is increased the cell will increase % of saturated fatty acids in membrane
Membrane bound organelles are present in what
Eukaryotes only
