Chapter 7.1 and 7.3 Review Guide

Question 1

What is the difference between a compound and simple lens microscope?

Answer 1

• Compound Microscope: Uses an objective lens and an ocular lens to magnify and object. It also can magnify up to 1000x. The specimen used must be thin enough for light to pass through. You can look at live specimen. Also, stains and fluorescent labels are used.
• Simple Lens Microscope: Uses one lens. Specimen must be thin enough for light to pass through. You can look at live specimen.

Question 2

Who invented the first microscope?

Answer 2

In the 1500s, two Dutch spectacle makers, Zaccharias Jonssen and his father Hans built the first microscope by lining up multiple lenses on a table.

Question 3

Who discovered and named the cell after observing cork?

Answer 3

Robert Hooke

Question 4

Who observed the first living cell?

Answer 4

Anton van Leeuwenhoek

Question 5

Distinguish between a compound light and electron microscope.

Answer 5

• Compound Light Microscope: Uses an objective lens and an ocular lens to magnify and object. It also can magnify up to 1000x. The specimen used must be thin enough for light to pass through. You can look at live specimen. Also, stains and fluorescent labels are used.
• Electron Microscope: Uses an electron beam to magnify objects. Can magnify up to 1000x smaller than a light microscope.

Question 6

What is the difference between a transmission and scanning electron microscope?

Answer 6

• Transmission Electron Microscope (TEM): Allows you to view cell structures and large protein molecules. Must use thin slices so image looks two-dimensional.
• Scanning Electron Microscope (SEM): Produces a three-dimensional images of the surface of your specimen.

Question 7

What did Schleiden conclude?

Answer 7

That all plants are made of cells.

Question 8

What did Schwann conclude?

Answer 8

That all animals were made of cells.

Question 9

What did Virchow conclude?

Answer 9

That cells come from other cells.

Question 10

What are the three things stated in the Cell Theory?

Answer 10

1. All living things are composed of cells.
2. Cells are the basic units of structure and function in living things.
3. New cells are produced from existing cells.

Question 11

What is the difference between a prokaryote and eukaryoute?

Answer 11

• Prokaryote: Do not contain a nucleus or membrane bound organelles. Ex: Bacteria
• Eukaryoute: Contains a nucleus and membrane bound organelles. Ex: Plants, Animals, Fungi, and Protists

Question 12

What do all cells have in common?

Answer 12

• They all have a cell membrane composed of phospholipids, proteins, and other macromolecules.

Question 13

What are the functions of the cell membrane?

Answer 13

• To regulate what goes in and out of the cell.

Question 14

Explain why the phospholipids are arranged as a bilayer.

Answer 14

• Because the phospholipids have hydrophobic fatty acid tails and hydrophilic phosphate head groups.

Question 15

Describe the Fluid Mosaic Model.

Answer 15

• The Fluid Mosaic Model shows that the membrane is a collage of proteins and other molecules embedded in the fluid matrix of the lipid bilayer.

Question 16

How do fatty acids affect the flexibility of the cell membrane?

Answer 16

• Fatty acids help the membrane stay viscous or less solid

Question 17

What is the role of cholesterol in animal cell membranes?

Answer 17

• In animal cells cholesterol help to prevent the peeking of fatty acid tails and thus lowers the requirement of unsaturated fatty acids. This helps maintain the fluid nature of the cell membrane without it becoming too liquid at body temperature.

Question 18

What is the role of carbohydrates in the cell membrane?

Answer 18

• Carbohydrates play a key role in cell-cell recognition or the ability to distinguish one cell from another. It also is important in organ and tissue development and it’s the basis for rejection of foreign cell by the immune system.

Question 19

What is the difference between integral and peripheral proteins?

Answer 19

• Integral Protein: They penetrate the lipid bilayer (usually across the whole membrane). It also acts as a trans-membrane protein and transports proteins in either a channel or pumping fashion.
• Peripheral Protein: They are loosely bound to the surface of the cell membrane and acts as a surface identity marker.

Question 20

What is another name for integral protein?

Answer 20

• Trans-membrane Protien

Question 21

What is the function of peripheral proteins in the cell membrane?

Answer 21

• It acts as a surface identity marker.

Question 22

22. What are the six functions of the integral proteins in the cell membrane?

Answer 22

1. Transporter: allows things to pass in and out
2. Enzyme Activity: speeds up chemical activity
3. Cell Surface Receptor: attaches to certain cells
4. Cell Surface Identity Marker: glycolipids and glycoprotiens
5. Cell Adhesion: forms a barrier and helps to stay together
6. Attachment to Cytoskeleton: provides shape to cell

Question 23

How do proteins stay anchored in the cell membrane?

Answer 23

• Within the membrane non-polar amino acids anchor proteins into the membrane. On the outer surface of the membrane polar amino acids extends into the extracellular fluid and into the cytosol.

Question 24

What is diffusion?

Answer 24

• Diffusion is the second law of Thermodynamics. It is the movement from high to low concentration.

Question 25

List three examples of passive transport.

Answer 25

• Food and energy going into a cell.
• Salt coming out of a cell.
• Carbon dioxide coming out of a cell.

Question 26

What materials do cell want to get into the cell?

Answer 26

• Foods such as carbohydrates, sugar, proteins, amino acids, lipids, salts, oxygen, and water.

Question 27

What material do cells want to get out of the cell?

Answer 27

• Waste products like ammonia, salts, carbon dioxide, water, and products.

Question 28

What molecules can pass directly through the cell membrane and why?

Answer 28

• Fats and other lipids because they’re non-polar.

Question 29

How do polar molecules, ions and large molecules get in and out of the cell?

Answer 29

• They travel in and out of the cell through protein channels.

Question 30

What does semi-permeable mean?

Answer 30

• Specific materials are allowed to go through

Question 31

What is osmosis?

Answer 31

The movement of water using the properties of diffusion

Question 32

Compare hypertonic, hypotonic, and isotonic solutions and explain what happens to a cell in each of them.

Answer 32

• Hypertonic: solutions have more solute, and less water. A cell would become smaller or dehydrated (crenation).
• Hypotonic: solutions have less solute, and more water. A cell would become larger and swell (lyse).
• Isotonic: solutions have equal solute, and equal water. A cell would stay the same.

Question 33

What is an aquaporin?

Answer 33

• The special protein channel that water uses to move in and out of a cell.

Question 34

How is active transport different than passive transport?

Answer 34

• Active Transport: Cells may need to move against the concentration gradient. The shape change transports solute from one side of the membrane to other (pump). Uses energy.
• Passive Transport: The diffusion of non-polar, hydrophilic molecules through a protein channel.

Question 35

How is active transport similar facilitated diffusion? How is it different?

Answer 35

• Active transport and facilitated diffusion both use energy to help molecules enter and leave a cell, but active transport goes against the concentration gradient.

Question 36

Distinguish between Endocytosis and Exocytosis.

Answer 36

• Endocytosis: into a cell

* Exocytosis: out of a cell