LEC EXAM #1 CHP 3 Flashcards
What is the endosymbiotic theory state?
Eukaryotes evolved from anaerobic bacteria (chloroplasts) and intracellular aerobic bacteria (mitochondria)
What is the evidence for this theory?
Mitochondria and chloroplasts have ribosomes, their own DNA, and reproduce by binary fission
Plasma membrane is comprised of:
Phospholipid bilayer-(double layer of phospholipid molecules)
functions of plasma membrane:
- barrier
- support
- regulates what comes in and out
How do we know the plasma membrane is fluid?
Fluid mosaic model
What does the fluid mosaic model describe the movement of plasma membrane is due to:
Unsaturated hydrophobic fatty acid tails kink
3 components of cytoplasm:
- cytosol: watery matrix
- organelles: little organs
- inclusions: store nutrients
Housed in centromere, forms spindle apparatus during cellular division and used in cilia and sperm flagella for movement:
Centrioles
Small extensions of the cell to increase surface area:
Microvilli
Small motile extensions of the cell surface, moves fluids across cell:
Cilia
Tail of sperm that consists of microtubules:
Flagella
Build polypeptides in protein synthesis:
Ribosomes
Free ribosomes in:
Fixed ribosomes attached to:
Cytoplasm
ER
Houses DNA, serves as cell’s control center:
Nucleus
- No ribosomes attached
- Synthesis lipids and carbs
- Breaks down glycogen->glucose
- absorbs and transports lipids
SER
- Covered in ribosomes
- protein synthesis
- folds polypeptides
RER
Where the ER empties their digestive enzyme, protein, and lipid contents
Golgi apparatus
Powerful, acidic, enzyme containing vesicles:
Lysosomes
Use carbs, lipids, and proteins to synthesize ATP:
Mitochondria
“Sugar coat”
Glycocalyx
Passive transports that do not require ATP:
Diffusion
Osmosis
Facilitated diffusion
What can passively pass through the plasma membrane?
anything that does not require ATP
When do we use diffusion for passive transport?
Small hydrophobic molecules, small polar molecules, gasses
When do we use osmosis for passive transports?
Osmosis of water
Osmosis:
Movement of water to the side with more particles
Hyposmotic:
Less particles outside the soln
Hyperosmotic:
More particles outside the solution
Tonicity:
how well a cell resists swelling/ how cell behaves inside soln depending on outside of cell
Hypertonic:
- more soln outside the cell
- water moves outside cell
- cell shrinks or crenates
Hypotonic
- less soln outside cell
- water moves inside cell
- cell swells up
Passive transport/facilitated diffusion:
moving ions or large polar molecules down their conc. gradient
2 types of transport proteins:
- channel: (ligand, voltage) transports sodium
- carrier: transport glucose and amino acids
Secondary active transport:
2nd pump that works at the same time as the primary pump to drive down coupled molecules, using less ATP
When a carrier protein is saturated…
the rate of transport is maximal.
Active transport:
Pumping substances across the membrane against their concentration gradient, requiring ATP
When a membrane-bound vesicle carrying substance fuses with the plasma membrane and secretes its contents to the cell’s exterior:
Exocytosis
When a substance is brought into the cell and the plasma membrane buds inward:
Endocytosis
3 examples of exocytosis:
- secretion of digestive enzymes by pancreas
- secretion of mucous by salivary glands
- secretion of milk by mammary glands
2 types of endocytosis:
- Phagocytosis
- Pinocytosis
Secondary messenger systems:
cAMP and G-protein coupled mechanisms
Tonicity deals with:
Osmosis deals with:
Solution
Solute particles
Why would you treat a patient with a 0.5%NaCl hypotonic soln?
To treat a patient with dehydration, because the lower concentration of solutes will move into the cell
