MC Test Flashcards
(32 cards)
1
Q
What does active transport require the cell to use and in the form of what? What does it create in the cell membrane?
A
- Energy in the form of ATP
- Creates a charge gradient in the cell membrane: For example in the mitochondria, hydrogen ion pumps hydrogen ions into the intermembrane space of the organelle as part of making ATP
- Transfer of partilces against charge gradient: low concentration to high concentration
- ATP = ADP+Pi
3Na+ 2K+
2
Q
How do Hypotonic solutions affect the water movement of the cell?
A
- Higher concentration of solute inside the cell and lower concentration of solute and more water outside the cell
- As a result, water diffuses into the cell, causing the cell to swell and possibly explode
- The cell expands
- Ex: Plasmolysis in plant cells
- Ex: Red blood cells that expand or are swollen and lysis-dilute
3
Q
How do hypertonic solutions affect water movement of the cell?
A
- Lower concentration of solute inside the cell and higher concentration of solute outside the cell
- Water flows out of the cell
- Cell shrinks
- Ex: Red blood cells shrinks (crenation)-concentrated
4
Q
How do Isotonic solutions affect the water movemnt of a cell?
A
- Water diffuses into and out of the cell at the same or equal rate
- Fluid that surrounds body cells is isotonic
- Water moves across the cell mebrane through special protein lined channels and if the total concentration of all dissolved soluted is not equal on both sides, there will be a net movement of water into or out of the cell which depends on the cells environment
- Ex: Normal red blood cells are isotonic
5
Q
What is Osmosis?
A
- Movement of water across the a semi permeable membrane from a lower concentration to higher concentration of solutes
6
Q
The two types of transport?
A
-
Passive Transport: Does not require energy and is dependent on permeability of cell membrane
- Diffusion: High to low concetration for phospholipids
- Osmosis: Low to high concentration, occurs in water
- Faciliatated diffusion: high to low concentration in proteins
-
Active transport
- transfer of particles against concentration gradient, from low concetration to high concentration and occurs in proteins
- Requires energy from ATP
7
Q
What is Facilitated diffusion? Describe the types of Facilitated diffusion.
A
- The process that does not require ATP but requires cell membrane proteins called carrier proteins to carry molecules across a cell membrane from higher concentration to an area of lower concentration
- Uniport: one particle goes from high conc. to low conc.
-
Cotransport:
- Symport: 2 particles transported in same direction
- Antiport: 2 particles transported in diff. direction
8
Q
What is diffusion?
A
- Net movement of particles from area of high conc. to low conc.
- Random movement of particles
- A passive process meaning no energy is needed
9
Q
Cell membranes are made of phospholipids…describe them
A
- Phospholipids have a hydrophilic(polar) head and hydrophobic(nonpolar) fatty acid tail
- Cholestrol onlu in animal cells-cell membrane
10
Q
Condensation and Evaporation
A
- Condensation: gas to liquid
- Evaporation: liquid to gas
11
Q
Freezing and Melting
A
- Freezing: liquid to solid
- Melting: solid to liquid
12
Q
Re-Sublimation and Sublimation
A
- Re-sublimation: gas to solid, ex: dew on grass
- Sublimation: solid to gas, ex: soap and the smell
*
13
Q
States of Matter
A
- All matter is made of small particles(atoms, molecules and ions)
- They are in constant random motion
- They constantly collide with each other and with the walls of the container
14
Q
Kinetic molecular theory of matter
A
- a model to explain behaviour of matter
- It postulates that:
- Matter is composed of small particles
- Kinetic energy: each particle is in constant motion
- Particles contain potential energy due to attractions and repulsions between them
- Particles move faster as temperature goes up
- Particles transfer energy during a collision with no net energy change
15
Q
Define Liquid
A
- The molecules that make up a liquid flow easily around one another
- They are kept from flying apart by attractive forces between them
- Liquids assume the shape of their container
16
Q
Define Gas
A
- The molecules that make up a gas fly is all directions at great speeds
- They are so far apart that the attractive forces between them are insignificant
17
Q
Define Plasma
A
- At very high temperatures of stars, atoms lose their electrons,
- The mixture of electrons and nuclei that results in the plasma state of matter
18
Q
Define Solid
A
- Regular repeating patterns, firmly in place, particles close to each other and strong attractive force, they vibrate within place
19
Q
Absorption
A
- Process by which matter or radiant energy is taken up internaly or assimilated by a substance
- Matter that is absorbed can be gas, solid or liquid
- Radiant energy includes light, heat, X rays, UV rays, radio waves and sound
- Sponge absorbing water and liquids
- Digested food absorbed by bloodstream through vili
- Plants absorbing water and nutrients from soil and leaves absorbing oxygen and carbon dioxide
- Production of energy in nuclear reactors: Neutrons absorbed by the nuclei of uranium and plutonium atoms which cause the nuclei to fission or split and in the process of spitting release additional neutrons
20
Q
Adsorption
A
- adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface
- Like surface tension, it is a surface energy based process while absorption involves volume of material
- This process creates a film of the adsorbate on the surface of the adsorbent
- In a bulk material, all the bonding requirements (be they ionic, covalent or metallic) of the constituent atoms of the material are filled by other atoms in the material.
- Atoms on the surface of the adsorbent attracts adsorbates because they are not surrounded by adsorbent atoms.
- Desorption is the reverse
21
Q
Hydrolysis for ATP, ADP, AMP
A
- ATP+H20 = ADP+Pi+E
- ADP+H2O = AMP+Pi+E
- AMP+Pi+E = ADP
- ADP+Pi+E = ATP
22
Q
Explain Surface Tension
(Definition, In bulk of the liquid, at the surface of the liquid, and molecules at the surface)
A
- Caused by attraction between the molecules of the liquid by various intermolecular forces
- In the bulk of the liquid, each molecule is pulled equally in all directions by neughbouring liquid molecules resulting in a net force of zero
- At the surface of the liquid, the molecules are pulled inwards by other molecules deeper inside liquid and are not attracted as intensely by molecules in the neighbouring medium(be it a vaccum, air or other liquid)
- All molecules at the surface are subject to an inward force of molecular attraction which is balanced only by resistance of liquid to compression, therefore there is no net inward force
23
Q
Formula for Surface tension
A
- Surface tension is (T) is a force (F ) which acts on unit of length (L) of a surface
- T=F/L , Answer in N/m (Newton meters), can be measured in dynes/cm
- ex: Water at 20 deg. cel. has a surface tension of 72.8 dynes/cm compared to 22.3 for ethyl alcohol and 465 for mercury
24
Q
What happens to surface tension when the temperature is higher in water?
A
Lower surface tension
Ex: Water temp Surface tension
0 75.64
10 74.22
15 73.49
20 72.75
25 71.97
25
What happens when the drving force diminishes surace area?
What happens to a surface due to surface area minimization?
* There is a driving force that diminishes surface area and in this respect, a **liquid surface resembles a stretched elastic membrane**
* As a result of **surface area minimization**, a surface will assume the smoothest shape it can
* *A molecule in contact with a neighbour is in a lower state of energy than if it werent in contact with a neighbour*
* Interior molecules all have as many neighours as they can possibly have but **boundary neighbours have lower neighbours than interior molecules and are molecules in a higher state of energy**
26
What is the resting membrane potential and active membrane potential in mV?
Resting: -70 mV and Active: +40mV
27
Describe Cohesion and Adhesion
* molecules in liquid state experience **strong intermolecular attractive forces**
* **Cohesion:** attractive forces between molecules, cohesive forces between liquid molecules are responsible for **surface tension**
* **Adhesion:** attractive forces between unlike molecules (ex: glass and water)
28
What is capillary action?
Describe the types of meniscus.
* result of **adhesion and surface tension**
* _Adhesion of water to the walls of a vessel_ will cause an upward force on the liquid at the edges and result in a **meniscus** which **turns upward**
* occurs when **adhesion to the walls is stronger** than the cohesive forces between the liquid molecules
* the height to which capillary action will take water in a uniform circular tube is limited by surface tension
* **Meniscus:** curve in the surface of a liquid and is produced in response to the surface of a container or another object
* The bottom of a **concave** meniscus(faces upward)
* The top of a **convex** mensicus(faces downward)
29
Describe **wetting** when attractive forces are below(\<90 deg) or exceed surface tension (\>90 deg)
* **\<90 deg**
* Liquid on a non wettable surface, _surface tension dominates_ the attractive forces
* _Convex miniscus_
* _Cohesion_ is stronger than adhesion
* Surface tension forces toward the center and gravitional force acting down
* **\>90 deg**
* _attractive forces_ to the surface exceed surface tension, the liquid wets the surface
* _adhesion_ is stronger than cohesion
* _concave meniscus_
* more surface attractive forces acting down
30
Examples of lowering surface tension
* **Soaps and detergents** help with cleaning of clothes by lowering surface tension of the water so that it more readily soaks into pores and soiled areas
* (hydrophilic polar head group and hydrophopbic non polar hydrocarbon chain)
* **Washing with cold water:** using hot water for washing because its surface tension is lower and it is a better wetting agent, but if detergent lowers surface tension then heating is unnecessary
* **Disinfectants:** solutions of lower surface tension. This allows them to spread out on cell walls of bacteria and disrupt them
* **Clinical test of Jaundice:** Surface tension of urine is 66 dynes/cm but if bile is present then, 55 dynes/cm
* **Water strider**: high surface tenison of water supports the tiny mass and geometry of is legs
31
What is wetting?
When a liquid is in contact with a solid surface, its behaviour depends on the relative magnitudes of the surface tension forces and attractive forces between the molecules of the liquid and of those comprising the surface
32
Adsorption-industrial applications
* Activated charcoal, capturing and using waste to provide cold water for air conditioning, synthetic resins, increase storage capacty of carbide derived carbons and water purification
* Adsorption, ion exchange, and chromatography are sorption processes where adsorbates are selectively transferred from the fluid phase to the surface of insoluble rigid particles suspended in a vesse or packed in a column
* Pharmaceutical applications are lesser known
