Homeostasis and Cell Transport

What is a lipid bilayer?

Two sheets of phospholipids on top of each other

What do cell membranes have imbedded?

Proteins going through it

(Blank) may be attached to (blank)

Carbohydrates may be attached to proteins

What makes up the Fluid Mosaic Model?

Proteins and lipids

Why is there fluid in the Fluid Mosaic Model?

So the lipids and proteins can move around

Is the fluid in the Fluid Mosaic Model the same as liquid?

No

What does fluid mean?

Moveable, not necessarily liquid

What does mosaic mean?

Pieces that go together

What takes up the majority of the cell membrane?

Lipid bilayer

Diffusion is what type of transport?

Passive

What does passive transport not need?

Energy

What is diff?sion>

Movement of particles from high to low concentration

What is concentration?

The amount of solute/solution

What does diffusion cause? Until what happens?

Particles to move across cell membrane until equilibrium is reached

What is equilibrium?

Equal concentration inside and outside of a cell

How much time does diffusion take?

Varies, depends on concentration, size, etc

What type of transport is facilitated diffusion?

Passive

What happens in facilitated diffusion?

Specific large particles diffuse through specific protein channels in the membrane

What does facilitated diffusion still require?

Concentration difference in and out of the cell

What is osmosis?

Facilitated diffusion of water through proteins

What is moving in osmosis?

Water only

What is isotonic osmosis?

Equilibrium of water and solute concentration

What is hypotonic osmosis?

Low concentration of solute

What is hypertonic osmosis?

High concentration of solute

Where does water always flow in osmosis?

Towards the hypertonic solution

What is the affect on the cell of hypertonic osmosis?

Shriveled cells

What is the affect on the cell of hypotonic osmosis?

Swells, bursts

What does active transport need?

Energy

How do the particles move in active transport?

From low to high conentration

What does active transport sometimes use to move particles up and down the membrane?

Sodium pumps

What is a form of active transport?

Bulk transport

Active transport will not...

Reach equilibrium

Where does endocytosis go?

Into the cell

Where does exocytosis go?

Out of the cell

What is exocytosis?

Removal of large amounts of materials from cells

What is endocytosis the movement of?

Large particles

What happens to the alrge particles in endocytosis?

Engulfed by the cell

What do large particles become in endocytosis?

Membrane bound vesicles in the cell

What are phagocytosis?

Large food particles

What are pinocytosis?

Small particles, liquids

What are the important components of the plasma membrane? (4)

Phospholipids, cholesterol, proteins, carbohydrates

What molecules can move through the plasma membrane by diffusion?

Lipid soluble molecules

What types of proteins are in the plasma membrane? (3)

Channel protein, glycoprotein, carrier protein

Where does water tend to move during osmosis?

Towards the solutes

What type of process is osmosis?

Passive, does not require energy

Why does actice transport require energy?

Going against the concentration gradient

Where does the energy for active transport come from?

ATP releasing energy after being hydrolyzed

What is an ion pump?

Special protein that transports ions against the concentration gradient

What is the term cotransport?

To move two substances

What does cotransport power?

The movement of one substance powers the movement of the other

What makes up the Fluid Mosaic Model?

Embedded proteins in the cell membrane

What is one phospholipid made up of?

One hydrophilic head and two hydrophobic tails

What is another specific type of lipid in the cell membrane?

A sterol

What does cholesterol help with in the plasma membrane?

Keeps the plasma membrane firm and stable over a wide range of temperatures

What function is primarily carried out by the carbohydrates present on the cell membrane?

Cell recognition

How long does diffusion continue?

Until the concentration gradient is eliminated

What can pass through the plasma membrane easier? Hydrophobic or hydrophilic molecules?

Hydrophobic molecules

What is a solution?

The mixture of of a solute in a solvent

Where does water move in general in osmosis?

Into and out of cells

What is the difference between primary and secondary active transport?

Primary uses direct ATP, secondary uses ion pumps from energy stored

What part of the phospholipid is polar?

Phosphate head

What part of the phospholipid is nonpolar?

Fatty acid tails

What are the proteins outside of the cell membrane called?

Peripheral proteins

What are the proteins going through the cell membrane called?

Integral proteins

What makes a protein a glycoprotein?

When a carbohydrate is attached

What are proteins that let water into the cell during osmosis called?

Aquaporins

Why can't the water molecules on the outside of a cell pass into the cell during hypertonic concentrations?

The solutes are obstructing their paths