Chapter 6 Flashcards
Explain the term “Regulation of life processes”
Every cell performs a function that contributes to our life and survival
What is the component of survival of species
Reproduction of individual cells
What is different about heart muscles?
They contain many mitochondria to supply the great amount of energy that the heart requires
What is special about sperm cells
They have flagellum for motility
What controls the movement or transportation of substances in and out of the cell
Cell membrane
Examples of molecules that would pass in and out of the cell
Water, oxygen, nutrients gasses and waste
What are the two methods of transportation
Passive and active transportation
What 2 characteristics define passive transport
It does not require any energy expenditure and run by movement down a concentration gradient
Name the 5 types of passive transport
- Simple diffusion
- Osmosis
- Dialysis
- Facilitated diffusion
- Filtration
Define how molecules spread out with diffusion
Spread out evenly throughout available space
DIffusion has movement of area of ______ concentration to _______ concentration
High, Low
What is a solute?
A dissolved substance
Where does simple diffusion occur?
Through a permeable phospholipid bilayer
What does permeant molecule mean
Can diffusion through membrane
What does impermeant molecule mean?
Can’t diffuse through a membrane
Osmosis is a special type of ________
DIffusion
What defines osmosis
When water can diffuse through a membrane while other solutes can not
What allows water to be permeable?
Aquaporins
What happens when water is added in a closed space?
Increase in pressure
Water pressure that develops in a solution as a result of osmosis is called________
Osmotic pressure
Where does osmotic pressure develop?
In the solution that originally had the highest concentration of impermeant solutes
What is hypotonic
Higher concentration of water outside the cell, resulting in water moving into the cell
What occurs when too much water moves into a cell
cytolysis also known as hemolysis for blood cell
What is isotonic
Same concentration of water inside the cell as outside
What is hypertonic
Higher concentration of water inside the cell resulting in water moving out
What happens when too much water diffuses out of a cell
Crenation (abnormal notching of cell due to contraction/shrinking)
What is dialysis
Special kind of diffusion where smaller molecules are separated from larger ones across a permeable membrane
Where is dialysis used?
Used in hemodialysis to clean blood of patients with kidney failure
What’s the difference between osmosis and dialysis
Diffusion of water vs solutes
What is facilitated diffusion
A special kind of diffusion in which movement of molecules is made more efficient by helps embedded within the cell membrane
How does facilitated diffusion transport substances ?
Down concentration gradient
What are the 2 types of facilitated diffusion
Channel mediated and carrier mediated
3 characteristics of channel mediated passive transport channels
- They are specific (only let certain solutes through)
- Allow membrane to be selectively permeable
- Channels can be closest and are activated by a variety of stimuli
Describe carrier mediated passive transport
Carriers attract the solute and bind to them. The carrier than changes its shape within the membrane and release the solute on the other side
Membrane carriers are usually _________ depending on _________
Reversible
The direction of the concentration gradient
What is the process of filtration
The forcing of water and permeable solutes through a membrane from high pressure to low pressure
What is the force pushing on the membrane in filtration called?
Hydrostatic pressure
What is an example of filtration in the body
Formation of urine by the kidneys
Active transport occurs only in ______ through ________
Living cells
Living membranes
Movement of the substances in active transport is
Low to high, against concentration gradient
Active transport requires what?
ATP
Types of active transport include
Membranes pumps and transport by vesicles
Two types of transport by vesicles are
Endocytosis and exocytosis
What is a membrane pump?
A protein complex in the cell membrane called a carrier
How do membrane pumps work
They use ATP to move substances across cell membranes against their concentration gradient
Many membrane pumps are specific to _____
Ions
What is endocytosis
Plasma membrane traps extra cellular material and brings it into the cell
What are the two types of endocytosis
Pianocytosis and phagocytosis
What is phagocytosis
“Cellular eating”
Large particles are engulfed by plasma membrane and enter the cell in vesicles
Vesicles from phagocytosis fuse with _____ which _____
lysosomes
Digest the particles
What is pinocytosis
“Cellular drinking”. Fluids enter the cell
What is receptor mediated endocytosis
membrane receptor molecules recognize substances to be brought into the cell
What is exocytosis
Intracellular material (usually proteins) are enclose in membraneous vesicles and released outside the cell
Which organelle is most associated with exocytosis
Golgi aparaus
What happens in exocytosis as the vesicles reaches the membrane?
The membranes fuse and the contents is released outside cell
What 2 other uses are there for endocytosis
Glandular secretions and building/repairing the plasma membrane
