Adapted from L. Miriello by D. Knuffke

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AP Biology Name _________________________ Reading Packet 2- Cells Unit Chapter 6: A Tour of the Cell

1. What is resolving power?

2. How is an electron microscope different from a light microscope and what is the difference between a scanning and transmission electron microscope?

3. Describe how cell fractionation is used to study organelles.

4. Label the prokaryotic cell below – list structure and function.

5. Why does the surface area to volume ratio limit the size of a cell?

Adapted from L. Miriello by D. Knuffke

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6. Explain how the structures listed below allow for the cell to accomplish specific function

a. Nucleus i. Nuclear envelope

ii. Nuclear lamina

iii. Chromosomes

iv. Chromatin

v. Nucleolus

b. Ribosomes

c. Endoplasmic reticulum i. Smooth ER

ii. Rough ER

d. Golgi Apparatus

e. Lysosomes

f. Vacuoles i. Food

ii. Contractile

iii. Central w/tonoplast

g. Mitochondria

h. Plastids

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i. Amyloplast

ii. Chromoplast

iii. Chloroplast

i. peroxisomes

j. cytoskeleton i. microtubules

1. centrosomes and centrioles

2. cilia and flagella – include basal body

ii. microfilaments

1. actin

2. myosin

3. pseudopodia

iii. intermediate filaments

k. Cell walls

l. Extracellular matrix

7. What are intercellular junctions and why are they important? 8. Using the table below, contrast plasmodesmata, tight junctions, desmosomes, and gap junctions.

Adapted from L. Miriello by D. Knuffke

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Intercellular Junction: Plant Cells or Animal Cells?

Can material move through them?

Example human body cell that has them:

Plasmodesmata

n/a

Tight Junctions

Desmosomes

Gap Junctions

Chapter 7: Membrane Structure and Function

1. Explain “selective permeability” and why cells need to be selectively permeable.

2. Give an example of an amphipathic molecule found in the cell membrane. Explain why it is amphpathic.

3. Explain the plasma membrane models proposed by the following scientists: a. Gorter and Grendel

b. Davison and Danielli

c. Singer and Nicolson

4. How did scientists use the freeze fracture technique to figure out the structure of the cell membrane.

5. How is the fluidity of cell membrane’s maintained? Explain the role of cholesterol.

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6. Label the diagram below – for each structure – briefly list it’s function:

7. List the six broad functions of membrane proteins.

8. How do glycolipids and glycoproteins help in cell to cell recognition?

9. Why is membrane sidedness an important concept in cell biology?

10. How do aquaporins increase the permeability of the cell membrane to water?

11. Explain the concept of the “concentration gradient”.

12. Fill in the following transport table:

Adapted from L. Miriello by D. Knuffke

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Diffusion Osmosis Active Transport Is Energy Required?

How do the molecules move (relate to the concentration gradient)?

Miscellaneous Question:

How does simple diffusion differ from facilitated diffusion?

Why is water balance important?

How do cells accomplish active transport?

13. Label the diagram below:

14. How is ATP specifically used in active transport?

15. Define and contrast the following terms: membrane potential, electrochemical gradient, electrogenic pump and proton pump.

16. What is cotransport and why is an advantage in living systems?

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17. What is a ligand?

18. Contrast the following terms: phagocytosis, pinocytosis and receptor-mediated endocytosis. Chapter 8: An Introduction to Metabolism

1. Contrast catabolic and anabolic pathways.

2. Define the following terms: a. Energy

b. Kinetic energy

c. Heat/thermal energy

d. Chemical energy

e. Thermodynamics

f. First Law of Thermodynamics

g. Second Law of Thermodynamics

h. Free Energy

3. Contrast exergonic and endergonic reactions in terms of: free energy, stability, capacity to do work.

4. How do you know if a reaction is spontaneous?

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5. Can a closed system at equilibrium do work? Why or why not?

6. List and give an example of the thee main kinds of cellular work done by ATP.

7. Label the diagram below and indicate how cellular work is done by ATP.

8. Define phosphorylated.

9. In your own works, explained the concept of coupled reactions and ATP doing work.

10. What is the relationship between exergonic reactions, endergonic reactions and the use and regeneration of ATP?

11. What is activation energy?

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12. Label the diagrams below including the change in free energy.

13. i. Define the following terms: a. Substrate

b. Enzyme substrate complex

c. Active site

d. Induced fit

ii. Label the diagram:

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14. How do temperate and pH (specifically) affect enzyme activity?

15. Compare and contrast competitive and noncompetitive inhibitors.

16. What is allosteric regulation and how does assist in the regulation of metabolism?

17. What is cooperativity?

18. How does feedback inhibition work?

Chapter 11: Cell Communication

1. What is a signal transduction pathway?

2. How do yeast cells communicate while mating?

3. How do intercellular connections function in cell-to-cell communication?

4. Explain the two types of local signaling: a. Paracrine signaling

b. Synaptic signaling

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5. Define the three stages of cell communication: a. Reception

b. Transduction

c. Response

6. How are intracellular receptors able to move through the cell membrane?

7. Label the diagram below of a steroid interacting with an intracellular receptor.

8. Where would you expect most water soluble messengers to bind and why?

9. What is a G-protein-linked receptor?

10. The G-protein-linked receptor is located ___________________. When GDP is attached to the G protein the

messenger is considered __________. GTP replaces GDP and now the messenger is considered ____________.

The G protein carrying the GTP leaves the receptor and _____________ an enzyme which causes a cellular

response. All of this is brought on by a ____________ _____________ attaching to the G-protein-linked receptor

and will shut down quickly when the ________________ _________________ is no longer there.

11. What is a kinase?

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12. A tyrosine kinase receptor is different from a G-protein linked receptor in that it can trigger ______________

_______________ ______________ pathway at the same time. When both ________________

_________________ are in their receptor sites, the molecules form a dimer – two molecules joined together. ATP

is converted to ADP and the ___________________ gets attached to the tyrosine molecules. The addition of the

_____________________ causes a cascade of cellular responses.

13. “Ligand gated” means controlled by the ______________ or signal molecule. If the door is closed, certain

_______________ are blocked from entering the cell. When the __________________ or signal molecule is

attached, the door is open for certain _________________ to enter the cell. These types of receptors are important

in the __________________ _____________________.

14. Phosphorylation cascades are similar to a row of dominoes falling down, instead of one domino knocking down the

next, a phosphate being added activates the message. In this way, a series of different ____________ are each

___________ one after another. Inactive protein kinase 1 gets a _____________ added and now it is

_____________ protein kinase 1. Active protein kinase 1 transfers a __________ and now inactive protein kinase 2

is now _______________. This continues until the desired ___________ is activated to cause a cellular response.

15. What are protein phosphatases and why are they so important?

16. What are second messengers and what are two characteristics of a second messenger?

17. What did Sutherland find in his experiments with regard to cyclic AMP and why is this important?

18. What is adenylyl cyclase?

19. How does the bacteria that causes cholera connect with the concepts of cell to cell communication?

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20. Complete the diagram below of cAMP as second messenger:

21. How and why are the calcium concentrations kept different and separate comparing the endoplasmic reticulum, mitochondria and cytoplasm?

22. Label the diagram below showing calcium and IP3 in a cell.

23. How is signal amplification accomplished in the cell?

24. How is specificity accomplished in cell signaling?

25. What is a scaffolding protein and why is it important?

26. How is termination of a signal accomplished and why is it so important that termination be accomplished?