Module 3 - Cells Flashcards
1
Q
permeability of lipid bilayer
A
- Oxygen, carbon dioxide, fatty acids & some steroid hormones easily pass-through cell membrane
- Not stopped by hydrophobic acid chains
- Special protein channels for water like substances & ions
2
Q
membrane proteins
A
- Receptors for attachment of chemical hormones & neurotransmitters
- Enzymes to help chemical reactions or breakdown molecules
- Ion channels allowing water like substances into cell
- Membrane transport carriers, transport across membrane
- Cell identity markers
3
Q
mechanisms to cross membranes
A
- Diffusion
- Active transport
- Osmosis
- Concentration gradients
- Sodium/Potassium pump
4
Q
mechanisms of diffusion
A
- Movement down concentration gradient
- Area of high concentration to area of low concentration
- Specific protein carriers that change shape (larger molecules)
- Charged molecules (+/-) move to area of opposite charge
5
Q
movement through protein channels
A
- Saturated system (all carriers are occupied) can’t work any faster
- Change in shape/configuration of carrier
- Specific carriers for specific substances
- Competitively inhibited by molecules of similar shape
6
Q
facilitated diffusion
A
- Transport of larger substances
- Attach to specific protein carrier
- Protein carrier undergoes change in shape
- Protein channel opens/protein rotates molecule to inner side
- Powered by concentration gradient (no energy required)
7
Q
active transport
A
- Requires protein carriers that span cell membrane
- Energy is needed to move molecules up concentration gradient
- Transport mechanism can be saturated & show chemical specificity
8
Q
osmosis
A
- Controls difference of water moving in & out of cell
- Movement of water down concentration gradient
- Water will move to area of high solute concentration (dilution)
- High solute concentration = low water concentration
- Water can only move through semi permeable membrane
9
Q
osmotic pressure
A
- Pressure applied to side with solution to stop fluid movement
- When semipermeable membrane separates a solution from pure water
10
Q
meaning of isotonic
A
- Same tonicit compared to cellular fluids
- No ability to cause osmosis
- little or no net movement of water across membrane
11
Q
meaning of hypertonic
A
- Higher tonicity compared to cellular fluids
- Causes osmosis, cell would shrink
- water moves out of cell
12
Q
meaning of hypotonic
A
- Lower tonicity compared to cellular fluids
- Causes osmosis, cell would swell
- water moves through membrane into cell
13
Q
equilibrium potentials
A
- Two ion forces chemical & electrical gradients
- Two forces equal in magnitude & heading in opposite directions
- No net movement, electrochemical equilibrium
14
Q
resting membrane potential
A
- Equal cations (outside) & anions (inside) cell membrane
- Establishes electrochemical difference (resting membrane potential)
- -70mV polarity
- Negative charge inside is greater that positive charge outside
15
Q
importat equilibrium potentials
A
- Potassium (K+) -90mV
- Sodium (Na+) +60mV
- Chloride (Cl-) -70mV
16
Q
function of chemical gradient
A
- Drives ion from area of high to low concentration
17
Q
function of electrical gradient
A
- Drives ion toward area that has opposite charge
18
Q
sodium/potassium pump
A
- Balances leakage of ions to maintain membrane potential
- Form of active transport, requires ATP
- 3 sodium ions out, 2 potassium ions in
19
Q
function of golgi apparatus
A
- packaging proteins
20
Q
function of secretory vesicle
A
- transport proteins out of cell
- secretion
21
Q
function of free ribosomes
A
- create proteins from amino acids
22
Q
function of lysosomes
A
- digestive system cell
- destroy bacteria
- breakdown biomolecules
23
Q
function of mitochondria
A
- ATP generation
- energy transfer & storage
- self replicate
24
Q
function of endoplasmic reticulum
A
- protein synthesis
- storage & transport of proteins/lipids
25
Q
function of cell membrane
A
- regulate passage of substances
- detect chemical signals from other cells
26
Q
function of centriole
A
- direct movement of DNA during cell division
- cylinder bundles of microtubules
27
Q
function of nucleus
A
- contains DNA that produces RNA in ribosomes
- within cell nucleus
28
Q
phospholipids
A
- composed of phosphate (head) & lipid (tail)
- phosphate head is hydrophilic (like water)
- lipid tail is hydrophobic (do not like water)
- when in water they form lipid bilayer (heads face out towards water & tails face in away from water)
- tails are barrier to water/water soluble substances (ions, glucose)
- fat soluble substances can can penetrate easily (oxygen, carbon dioxide)
29
Q
concentration of fluid inside typical human cell
A
- 300 mOsm/kg water
30
Q
tonicity
A
- ability of solution cause osmosis across biological cell membrane
- dependent on number of non penetrating solute molecules in a solution
31
Q
solute
A
- what’s being dissolved
32
Q
solvent
A
- what’s doing the dissolving (water)
33
Q
solute + solvent
A
- solution
34
Q
units of osmosis
A
- osmole
- used to describe number of particle in a solution that causes osmosis
- osmotically active particles (ex. Na+, Cl-, K+, glucose)
35
Q
units of concentration
A
- number of osmotic particles (osmol/volume of solution)
- omolaity, number of osmoses per kg of water
- osmolarity, number of osmoses per L of solution
36
Q
osmolality calculation
1 molar solution of NaCl is made up of 1 mole of NaCl in 1 kg of water
In water, NaCl will dissociate to 1 mole of Na+ ions and 1 mole of Cl- ions (both are osmotically active particles)
A
- the number of osmotically active particles is (1 Na+ + 1 Cl- )= 2
- Osmolality = 2 osmol/kg of water
