Module 4 Flashcards
A ___ is the basic unit of all living things
Cell
Describe Eukaryotic cells
Complex cells with a membrane-bound nucleus & subcellular structures
All fungi, plants, and animals(including humans) are ___
Eukaryotes
Describe prokaryotic cells
- Simple cells
- most are unicellular organisms
Cells are organized into what two things?
Tissues & organs
What’s a plasma membrane?
A covering that regulates what comes into or leaves from the cell
What’s cytoplasm made up of?
Mixture or water, salts, proteins, & organelles
What’s the nucleus?
The control center of the cell
What’s the cytoplasm
A gelatin-like substance, plus structural fibers and organelles(but not the nucleus)
4 functions of the plasma membrane
1) covers and protects the cell
2) controls what goes in and out
3) links to other cells
4) tells other cells who it is
2 functions of cytoplasm & 2 things that cytoplasm is compromised of
1) gives cell it’s shape
2) contains structural(cytoskeleton) proteins
1) organelles except nucleus
2) cytosol
Where is the genetic information stored in a cells
Nucleus
What is the blueprints for the cells of the body?
DNA
What are somatic cells?
Those that are not part of the reproductive system which includes sperm & egg
RNA is made in ______
The nucleus
RNA is exported into the ____
Cytoplasm
What makes proteins in the cell?
RNA
What’s the fluid-mosaic model?
- lipid “sea” with protein “icebergs” floating in it
- proteins are integral or peripheral
What does integral mean
Embedded in bilayer, go from one side to the other (transmembrane proteins)
What does peripheral mean in terms of cells?
Associated with inside or outside of cell
Describe inside peripheral
Link cytoskeleton to membrane
Describe outside peripheral
Link cell to connective tissue or to other cells
Plasma membrane looks like ______
2 parallel lines 80 nm apart
In terms of the plasma membrane, what do the parallel lines, which are polar head groups, bind to?
Osmium atoms…which are used as a stain in electron microscopy
Describe intergral(transmembrane) proteins?
Span the cell membrane from outside to inside the cell
Do the peripheral membrane proteins cross lipid bilayer?
No
Do transmembrane proteins cross lipid bilayer?
Yes
Describe location of peripheral membrane proteins
Loosely associated with the cell membrane and lie - completely in the outside
- completely on the inside of the cell
What’s an aquaporin?
A water pore protein
What does permeability tell us?
How easily a substance can cross the plasma membrane
What’s differential permeability?
What defines a cell
- the cell lets some things pass
• water and cell nutrients mud be allowed into the cells
- the cell does not let other things pass
• the “guts” of the cell should not leak
out
• toxic substances should not leak in
What does semi-permeable mean?
Certain things can pass, certain things can not
Why do gases pass easily through the lipid bilayer?
Because a gas molecule is small and non-charged
Name 2 fat-soluble molecules that pass the lipid bilayer easily
Butane & propane
Do charged ions and large molecules pass through the lipid bilayer without assistance?
No
What’s the rule of thumb?
Small, neutrally-charged, lipid-soluble substances can pass without assistance
Name 3 things that can pass a cell membrane which is selectively permeable from passing easily to not passing without help.
- Gases
- small, fat-soluble molecules
- charges ions, large, water-soluble molecules
What are the 6 categories of membrane proteins?
- ion channels
- carriers
- receptors
- enzymes
- linkers
- cell identity markers
