Bio Quiz 2 Flashcards
What five things are included in a cell membrane?
Proteins (channel and carrier) Phospholipids Phospholipid bilayer Carbohydrates Cholesterol
What makes a cell membrane an open structure?
The flow of matter and energy between a cell and it’s environment makes it an open system
What are proteins?
Can be integral or peripheral
Move substances across the membrane and carry out chemical reactions
What are phospholipids?
Primary compound of the membrane
Each has a head and tail
Hydrophilic head - water loving
Hydrophobic tail -water fearing ( found in the middle of the membrane)
What is the phospholipid bilayer?
Made up of hydrophilic heads and hydrophobic tails to form a membrane wall
What are carbohydrates?
Important for cell to cell communication?
What is cholesterol?
Helps to make the plasma membrane slightly more rigid in the area they imbed.
Also a function in cell communication
Explain the fluid mosaic model
Fluid : the membrane can flow but isn’t too rigid
Mosaic : the cell membrane is made of many different parts
What is a selective filter?
It regulates the movement of substances in and out of the cell.
Semipermeable - particles are let in and out bases on size, shape and electrical charge
What is Brownian motion?
According to the particle model of matter, all particle are in constant random motion
What are concentration gradients?
Particles will naturally moves from a high concentration area to a low concentration area.
What is equilibrium?
Occurs when particles are evenly distributed
What are the three kinds of passive transport?
Diffusion.
Osmosis
Facilitated diffusion
What is diffusion?
Uses the movement of particles from a high concentration to a low concentration until equilibrium is reached
What is osmosis?
Uses the movement of particles from a high concentration to a low concentration until equilibrium is reached but only for water
What is hypertonic?
A solution that has a higher concentration of solutes than inside the cell. Corn syrup/ egg experiment
What is hypotonic?
A solution the has a lower concentration of solutes then inside a cell.
Water /egg experiments
What is isotonic?
A solution with the same concentration inside and outside the cell.
What is facilitated diffusion?
Uses the concentration gradient BUT with the help of a protein facilitator.
What do channel proteins do?
Create pores through which small molecules may move
Facilitated diffusion
What do carrier proteins do?
Attach to larger molecules, change shape and physically move the molecule across the membrane
What is active transport?
The transported of molecules and nutrients into the cell using ATP energy created by the mitochondria.
What is endocytosis?
Uptake of particles by the formation of vesicles. The cell membrane encloses material and the pinches off to form a vesicle.
Phagocytosis - taking in large particles
Pinocytosis - taking in droplets of fluid
Receptor mediated endocytosis
What is exocytosis?
The excretion of molecules from a vesicle that bonds within the cell to the cell membrane to exit the cell.
