Chapter 7 Review!

Cellular Structure and Function

Directions • Work in a group of 3-4 students • We will go group by group to answer a question.• If a group cannot answer a question correctly,

the first group to raise their hand and is called on may answer the question.

• There is no penalty for guessing. • Team with the most points at the end wins! • I may deduct points for disruptive behavior …

Here we go …

Good luck!

An electron microscope can magnify an object about how

many times?

500,000

A light microscope can magnify an object how many times?

1,000

List the 3 principles of the cell theory

1. All living organisms are composed of cells

2. Cells are the basic unit of life3. Cells come from pre-existing cells

Define: organelle

Specialized structure which carries out a specialized function.

If a cell has a cell wall, is it a plant cell or an animal cell? How

do you know? Plant cell b/c animal cells do not

have cell walls.

What is the function of the lysosome?

Digests & breaks down worn-down organelles and food

particles.

Which organelle converts sugars into energy? (In an animal cell)

The mitochondria

Where are proteins made?

In the ribosomes

What is the function of the nucleus?

Control center; holds DNA (genetic information)

Cells fall into two broad categories. What are they?

Prokaryotes & Eukaryotes

The major structural difference between prokaryotes and the

eukaryotes is … The nucleus … prokaryotes don’t have a nucleus & eukaryotes do

have a nucleus.

Describe a eukaryotic cell.

*contain a nucleus*has organelles*larger & more complex than prokaryotes

What are examples of eukaryotic cells?

Plants and animals

Describe a prokaryotic cell.

*no nucleus or membrane bound organelles*smaller, simpler than eukaryotic cells

What’s an example of a prokaryotic cell?

Bacteria

Both eukaryotes and prokaryotes have a …

Plasma membrane

What is the function of the plasma membrane?

It regulates what enters and leaves the cell through selective

permeability.

Why is the plasma membrane called a fluid mosaic model?

It has a lot of different components and has fluidity

Describe the structure of the phospholipid bilayer.

It has two layers of phospholipids arranged tail-to-tail

The heads of a phospholipid are (polar/non-polar) and the tails are

(polar/non-polar)Heads: polar

Tails: non-polar

Why are the non-polar tails pointing inward?

Because they are hydrophobic and are being shielded from the

watery interior and exterior

Besides phospholipids, list three other components of the plasma

membrane. Transport proteins, cholesterol,

carbohydrate chains.

What is the function of cholesterol in the plasma

membrane? It helps maintain fluidity – keeps the tails from sticking together

What is the function of the carbohydrates attached to the

proteins? Define a cell’s characteristics and

helps the cell identify chemical signals

Identify A, B, C, D, & E in the diagram.

What do you think would happen to the plasma membrane if the

cholesterol was removed? The membrane would become

more rigid because the cholesterol helps with fluidity.

Define: homeostasis

Maintaining an internal balance

What characteristic of the plasma membrane maintains a cell’s

homeostasis? Selective permeability

True or false: Passive transport requires energy.

FALSE!

List three examples of passive transport.

1. Diffusion2. Facilitated diffusion3. Osmosis

In diffusion, molecules move from an area of ____ concentration to an area of ____ concentration.

High, low

How does facilitated diffusion differ from diffusion?

Instead of molecules passing directly through the plasma membrane, molecules pass through transport proteins.

Active transport requires …

ENERGY!

Na/K pump, endocytosis, and exocytosis are examples of …

Active transport … molecules are moving against its concentration

gradient & requires energy

This is a picture of what type of transport?

Our goal …

Is for EVERYONE to earn an 80% (a B or better!) on exam!