Ch 5 Reading Guide PDF

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Preclass reading assignment chapter 5...

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Chapter 5 Biol 150

Reading guide Dr. DeVito Martin, Fall 2016 Reading guide for Chapter 5 Sections 5.1, 5.2, 5.3, 5.4

Complete this reading guide as you read the textbook pages listed above. You might not have to read every word on every page, rather pay close attention to the questions in this guide and answer them as you work through the textbook. Also pay close attention to the terms that are underlined: these are key terms that you should know the definitions of and be able to apply in new situations. Section 5.1 Define amphipathic. How does a phospholipid fit this definition?

Compare and contrast micelles and bilayers. What properties of lipids lead to micelles vs. bilayers?

How freely can lipids move within a membrane? How do the following factors restrict movement of lipids within a membrane? -Length of fatty acid tails

-van Der Waals forces

-Presence/absence of double bonds between Carbon atoms

-Lipids other than fatty acids that have different structures (e.g. cholesterol)

-Temperature

What is a lipid raft? What do lipid rafts mean in terms of uniformity of the lipid bilayer?

Describe the following functions of proteins associated with cell membranes: -Protein Transporters:

-Protein receptors:

-Enzymes:

-Anchors:

What is the difference between integral membrane proteins and peripheral membrane proteins?

What chemical properties do transmembrane proteins have that allow them to span the entire membrane?

Describe the fluid mosaic model of the membrane.

What does FRAP: Fluorescent recover after photobleaching tell us about the mobility of molecules in a membrane? (See Fig. 5.8)

Section 5.2 How does the selectively permeable nature of the plasma membrane relate to maintaining homeostasis within the cell?

Diffusion leads to a net movement of a substance from a region of ___________ concentration to _________ concentration. When there is no difference in concentration, movement of the substance continues, but there is _______ net movement.

Name three molecules that can diffuse through the plasma membrane.

Define facilitated diffusion. What makes facilitated diffusion different from simple diffusion?

Facilitated diffusion utilizes two membrane transporters that bind to and allow molecules across the plasma membrane. Define a channel.

Define a carrier. What two conformations are possible?

Water moves across the membrane through both simple and facilitated diffusion. What protein channel moves water across the plasma membrane via facilitated diffusion?

Define osmosis.

Water concentration increases/decreases (circle one) as solute concentration increases/decreases (circle one). Define active transport. What does active transport require that diffusion (both simple and facilitated) does not?

Primary Active Transport utilizes ______ directly as an energy source.

Sodium-potassium pumps are known as ___________, and move ______ and ______ in same/opposite (circle correct) direction(s).

Symporters, also known as cotransporters are transporters that move two molecules in the same/opposite (circle correct) direction(s).

How does Secondary active transport use a buildup of concentration of a small ion to drive movement of other substances against their concentration gradient?

Define an electrochemical gradient.

What is the difference between a hypotonic and hypertonic solution? What happens to a cell placed in each solution, and why?

How do human red blood cells maintain an isotonic intracellular environment?

Cell walls resist expansion but provide structural _________ and protection to the cell.

What is turgor pressure?

When a plant cell absorbs water, cell walls allow pressure to increase/decrease (circle one).

Section 5.3 A cell is classified as a prokaryote or eukaryote based on the presence or absence of a ______.

Where is DNA stored in prokaryotes?

Define a plasmid. How are they shared between bacteria?

How does the small size of prokaryotes affect its surface area/volume ratio? How does this surface area/volume ratio impact the cells ability to absorb nutrients from the environment?

For each of the following eukaryotic organelles, describe its function and is it defined by a membrane? -Endoplasmic reticulum (ER)

-Golgi apparatus

-Lysosome

-Mitochondria

-Cytoskeleton

Section 5.4 How do vesicles allow connections between organelles?

What is the endomembrane system? What organelles are included?

Are extensive internal membranes a part of prokaryotic cells?

What are the benefits of compartmentalizing the cell?

What are endocytosis and exocytosis? How are these processes essential for moving material in and out of cells?

What is the nuclear envelope? How many membranes are involved?

How does material move in and out of the nuclear envelope?

mRNA moves out of the nuclear envelope through ________ __________. It then binds with ribosomes that are free in the __________ or ribosomes that are associated with the ________ __________.

How is the ER associated with the nuclear envelope?

What is the purpose of the ER? What does it produce and transport?

The interior of the ER is known as the ____________. What is the difference between the rough ER and the smooth ER. Why do they look different? What is synthesized in each portion of the ER?

What are the THREE roles of the golgi apparatus?

What is glycosylation? What types of proteins are typically glycosylated?

What is the purpose of the lysosome?

Why is it essential that the lysosome has a different chemical environment from other parts of the cell?

Proteins produced on ribosomes free in the cytosol are then __________.

What is a signal sequence? What types of signal sequences are there? Where do they direct proteins to?

Where can proteins end up that are produced on ribosomes on the rough ER?

What is the purpose of a signal recognition particle (SRP). How does it direct proteins to their final destination?

How are transmembrane proteins produced so that they are in the proper location?

You are now ready to complete the pre-class LaunchPad Quiz....