Biology - Cell Transport Test

Cell membrane names (3)

Cell membrane

Plasma membrane

Phospholipid Bilayer

Purpose (2)

1. Barrier to prevent contents of the cell from leaking

2. Allows things to enter and exit the cell

Individual organelles can also have this kind of membrane - True or False

True

What other organelles have these membranes?

1. Lysosomes 

2. Mitochondria 

3. Chloroplasts

4. Golgi apparatus 

5. Endoplasmic Reticulum 

6. Nucleus 

7. Vacuoles 

What organelles have double membranes?

Mitochondria and Chloroplasts

Cell membrane can also be called the _____________ model

Fluid mosaic model

Explain why the cell membrane is called the fluid mosaic model

It’s a fluid membrane with proteins embedded in it like fluid cement with stones embedded.

What makes the membrane fluid?

Phospholipid movement

The membrane is around the same consistency as _________

Salad dressing

If membrane becomes to fluid, what will happen?

The phospholipids will be too far apart, and the membrane won’t be in it’s place, so it won’t work.

If membrane isn’t fluid enough, what will happen?

The proteins wont function properly

What happens if a cell’s temperature drops

The phospholipids will start packing in tightly together, and membrane will become solid

What happens if a cell’s temperature rises

The phospholipids will move to fast and will die out

What is cholesterol’s purpose?

To maintain membrane fluidity

Where is cholesterol found?

Between phospholipids

What does cholesterol do if temperature rises?

Compacts phospholipids to prevent movement 

What does cholesterol do if temperature drops?

Separates phospholipids to prevent compacting

What six components make up the cell membrane

1. phosopholipids

2. integral proteins

3. peripheral proteins

4. carbohydrate side chain

5. glycoproteins

6. glycolipids

Phospholipid - purpose

Act as base/filling in membrane

Phosopholipids are composed of :

Hydrophilic heads and hydrophobic tails

What are phospholipid heads made up of

alcohol and glycerol

What are phospholipid tails made up of

fatty acids

Carbohydrate side chain - purpose

Cell to cell identification and recognition

Two things a carbohydrate side chain can attach to:

Glycoprotein (a protein) or glycolipid (a phospholipid)

What are 5 protein functions?

Transport, Enzyme Activity, Signal Transduction, Recognition for Cells, Inter-cellular Joining

(Acrynom = The elephant sleeps really joyfully)

Transport (function of proteins)

Proteins are a channel that allow certain substances to move in and out of the cell

Enzyme Activity (function of proteins)

Proteins can be enzymes, and enzymes help the cell speed up chemical reactions

Signal Transduction (function of proteins)

Membrane proteins can be receptors for specific molecules (usually a hormone), the hormone causes the protein to change shape, and the shape change sends a message/instruction to the cell

Recognition (function of proteins)

Proteins can be glycoproteins and have carbohydrate side chains that allow other cells to recognize

Inter-cellular joining (function of proteins)

Proteins connect to membrane proteins of other cells to join the cells together

What happens to red blood cells in hypertonic solution?

They lose water and become crenated (shriveled up)

What happens to red blood cells in isotonic solution?

Water leaves and enters equally, ideal sollution for red blood cells

What happens to red blood cells in hypotonic solution?

Water enters the cell; lyse/cytolysis (cell bursting)

What happens to plant cells in hypertonic solution?

Water leaves cell; plasmolysis (cell contents pull away from cell wall)

What happens to plant cells in isotonic solution?

Water enters and exits; it’s flaccid/limp

What happens to plant cells in hypotonic solution?

Water enters cell, causing high turgor pressure; ideal solution for plant cells

Turgor pressure

The pressure in plant cells that pushes the plasma membrane against the cell wall

Two types of transport

Passive and active

Passive transport

Movement of a substance from an area of high concentration to an area of low concentration without the expenditure of cellular energy 

Passive transport - types

Diffusion, including simple diffusion, osmosis, and facilitated diffusion

Diffusion

The movement of a substance from an area of high concentration to an area of low concentration

Simple diffusion

Diffusion in cases where molecules pass right through phospholipids into cell

Facilitated diffusion

Diffusion in cases where molecules need help from an integral protein 

Osmosis

The movement of water from an area of high concentration to an area of low concentration

Solution

Mixture in which one substance is dissolved in another

Solute

Substance that is being dissolved

Solvent

Substance that does the dissolving

Solvent types (3)

Hypertonic, isotonic, and hypotonic

Hypertonic solution

Solution containing more solute than another solution

Hypertonic solution - cause

Shrink cells by moving water out of cells

Isotonic solution

Solution containing the same amount of solute as another solution

Isotonic solution - cause

Doesn’t change size of cell

Hypotonic solution

Solution containing less solute than another solution

Hypotonic solution - cause

Increases the size of cells because water moves into them

Active transport

Type of transport that requires the cell to use energy, often moving a solute against concentration gradient (from low concentration to high) 

ATP

Fuels cell with energy for active transport

Bulk transport

Moving large molecules into and out of cells, needs active transport

Active transport types (2)

Endocytosis and exocytosis

Endocytosis

Method cell uses to move bulky items into cell

Endocytosis types (3)

Pinocytosis, phagocytosis, and receptor-mediated endocytosis

Pinocytosis

Cellular drinking

Phagocytosis

Cellular eating

Receptor mediated endocytosis

Highly selective; certain molecules attach to receptors on membrane, and cell brings them in

Exocytosis

Method cell to transport large molecules it made out of the cell

Selective permeability

When cells only let certain things through their membrane