Cell Membrane & Transport

Cell Membrane & Transport

Membrane Function

--Boundary between cell & Environ.

--Controls entry & exit to cell

--Organelle/Component protection

Multiple Choice

Which of the following is NOT a function of the cell membrane?

• Produce ATP for the cell

• Protection for the cell

• Control what enters and exits cell

Phospholipid

• Main component of membrane

• Double layer

• Has 3 main components

Multiple Choice

What type of biomolecule is found in the highest amounts of the cell membrane?

• Lipid

• Carbohydrates

• Phospholipid

• Nucleic Acids

Multiple Select

Which of the following are components of a phospholipid. Select all correct answers.

• Phosphate

• Protein

• Glycerol

• Fatty Acid Tails

• Nitrogen

Other Components

• Cholesterol : Structure

• Protein : Transport & Support

• Carbohydrates : ID tags

Multiple Choice

What is the purpose of cholesterol molecules in the cell membrane?

• Structure/Support

• Transport Molecules

• Cell Identification

• Ward off "invaders"

FLUID MOSAIC

Flexible & made of many componenets

Multiple Select

Select all components of the cell membrane that makes it a "mosaic"

• Phospholipids

• Proteins

• Carbohydrates

• Cholesterol

• Nitrogen

Selective Permeability

• Semipermeable

  --Letting somethings, but not all in

• Move through phospholipids

  --Small Non Polar Molecules

• Charged Molecules

  --Rejected

Open Ended

Explain why the cell membrane is considered both a fluid mosaic model AND semipermeable.

Cell Transport

• 2 major types

• Passive Transport

  --No energy required

• Active Transport

  --ATP (energy) required

Multiple Choice

What molecule is needed for active transport?

• Phopholipids

• ADP

• Glucose

• ATP

Concentration Gradient

Molecules tend to move DOWN a gradient; from high concentration to low concentration

Diffusion

Molecules moving from a high concentration to low concentration

Can be through a semipermeable membrane

Multiple Choice

What do molecules have to flow through in diffusion?

• Nothing

• Chicken Wire

• A semipermeable membrane

• A selection process

Osmosis

WATER

Water moving an area of HIGH WATER concentration to an area of LOW WATER concentration

Multiple Choice

The movement of water from an area of high water concentration to an area of low water concentration is called....?

• Diffusion

• Osmosis

• Active Transport

• Magic

Osmosis

• 3 Solution Types

• Hypotonic

  --More water flows INTO the cell

• Hypertonic

  --More water OUT of cell

• Isotonic

  Equal water flow in & out of cell

Multiple Choice

When the water is moving into and out of the cell at equal amounts, the solution is considered....?

• Isotonic

• Hypotonic

• Hypertonic

• Hypothesis

Multiple Choice

When the water is moving into the cell at a higher rate than out, the solution is considered....?

• Isotonic

• Hypotonic

• Hypertonic

• Hypothesis

Multiple Choice

You take a stalk (piece) of celery that is wilting and place it into a cup of water. Where will the water flow?

• Into the celery

• Out of the celery

• Not at all

• Turns into a gas and evaporates

Facilitated Diffusion

Molecules moving from high to low concentration

Using transport protein

--molecules need proteins because they would "get stuck" in phospholipids

Multiple Select

Which of the following is required for facilitated diffusion? Choose all correct answers

• ATP

• Transport Protein

• Concentration Gradient

• ADP

• Molecules

Active Transport

Requires

--Energy

--Transport Protein

Against concentration gradient

--low to high concentration

Endocytosis

• Cells taking in nutrients

• Folds membrane inwards

• Forms vesicle

Exocytosis

• Vesicle pushes into cell membrane

• Attaches to cell membrane

• Pushes out unneeded molecules

Multiple Choice

Which of the following forms of cell transport uses a vesicle to expel (get rid of) waste from the cell?

• Osmosis

• Diffusion

• Endocytosis

• Exocytosis