Biology 12

Name:

Cell Biology

Per:

KEY Date:

Chapter 3 – Cell Structures & Functions Complete using BC Biology 12, pages 62 - 107

3.1

The Cellular Level of Organization

pages 66 - 67

1. The macromolecules, such as carbohydrates and nucleic acids, discussed in the last chapter are not alive, yet the (a) (b) cell is alive. The cell is the structural and functional unit (c) of an organism. It is the smallest unit capable of performing all the functions necessary for life 2. History of microscopy: name the scientist that made the following contributions to cell biology 1

C 3

V

I

5

Across

S 2

S

R C H O W

C

L

H

E

W

I

A

D

N

3. 5. 4

Down H O

L E E U W E N H O E K N

Concluded that all cells come from preexisting cells. Made some of the earliest microscopes.

K

1. 2. 4.

E

Stated that plants are composed of cells. Stated that animals are made up of living units called cells. First used the term "cell" to refer to the honeycomb structure of cork observed in the microscope.

3. The cell theory is a basic theory of biology which states  All organisms are made up of basic living units called cells  All cells come only from previously existing cells 4. Complete the following table. Cube side length

Surface Area (6s2)

Volume (l x w x h)

SA:V Ratio

1 cm

6 (12) = 6

13 = 1

6:1

2 cm

6 (22) = 24

23 = 8

24 : 8 = 3 : 1

3 cm

6 (32) = 54

33 = 27

54 : 27 = 2 : 1

4 cm

6 (42) = 96

43 = 64

96 : 64 = 1.5 : 1

5. Using the information from the table above, explain why humans are made up of trillions of small cells instead of just big one. Amount of SA affects the ability to get materials in and out of the cell. Also, larger cells need more nutrients and produce more wastes BUT have a low SA:V ratio. This is inadequate to sustain the needs of the cell.

6. Why are there some cells that are much larger, even visible to the human eye, such as a chicken egg? These types of cells are not actively metabolizing like other cells. Once fertilized, their metabolism kicks in and they divide internally into smaller and smaller cells. 7. Give an example of a modification utilized by cells that specialize in absorption. Columnar epithelial cells along intestine surface are highly folded into microvilli to increase SA

3.2

Eukaryotic Cells

pages 67 - 77

(a) 8. All cells are surrounded by a plasma membrane consisting of a phospholipid (b) (c) bilayer embedded with protein molecules. 9. Describe the composition of cytoplasm. Water, salts, dissolved organic molecules 10. Define organelle: Any well-defined subcellular structure that performs a particular function for the cell

11. Identify the organelles on the following diagram. Use Figure 3.3 on page 70 to help.

nucleolus

nucleus

chromatin

vesicle or lysosome smooth ER

centrosome (or centrioles)

Golgi apparatus cytoskeleton rough ER

mitochondria plasma membrane

cytoplasm

ribosome

12. Match the functions of the organelles to their correct descriptions. B cytoskeleton A. cellular respiration (production of energy) G

Golgi apparatus

B. shape of cell and movement of its parts

A

mitochondria

C. lipid synthesis, tasks vary depending on type of cell

J

nucleus

D. regulates molecule passage into and out of cells

H

peroxisomes

E. storage of substances

D

plasma membrane

F. folding, modification, and transport of proteins

I

ribosomes

G. processing, packaging and distribution of proteins and lipids

F

rough endoplasmic reticulum

H. various metabolic tasks

C

smooth endoplasmic reticulum I. protein synthesis

E

vacuoles and vesicles

J. storage of genetic information; synthesis of DNA and RNAhe

Cytoskeleton

pages 77 - 80

13. Briefly describe the specific parts of the nucleus 

chromatin: DNA & associated proteins (“loose” DNA)



chromosomes: condensed DNA (just before cell division)



nucleoplasm: the cytoplasm of the nucleus



nucleolus: rRNA production and formation of ribosome subunits



nuclear envelope: double membrane around nucleus

 nuclear pores: allows proteins, ribosome subunits, etc to enter and exit the nucleus 14. Where in the cell are ribosomes found? Floating in cytoplasm (can be polyribosomes) and attached to rough ER 15. The endomembrane system consists of the: 

nuclear envelope



endoplasmic reticulum (smooth and rough)



Golgi apparatus

 vesicles 16. How does the Golgi apparatus known whether the proteins made at the rough ER belong inside the cell or are to be transported out of the cell? specific molecular tags like “postal codes” 17. Name three functions of lysosomes. (1) digest materials that come into the cell (e.g. breakdown polymers) (2) immune system aid (e.g. destroy pathogens) (3) autodigestion (e.g. breaking down old or unneeded cell parts)

18. Use Figure 3.7 on page 74 to identify the missing labels in the diagram below. plasma membrane

secretory vesicle

incoming vesicle

Golgi apparatus lysosome

transport vesicle

transport vesicle

rough ER

smooth ER

19. Where in the body do we have cells that contain high numbers of peroxisomes? liver 20. Contrast animal and plant cells (based on organelles or specific organelle functions). 

Unique to animal cells i. lysosomes ii. centrosome / centrioles iii. peroxisomes: break down fat, produce bile salts

* cilia & flagella rare for plants



Unique to plant cells i. chloroplasts ii. cell wall iii. large central vacuole 21. Plants have chloroplasts the process of photosynthesis solar energy

(a)

+

CO2

+

which use solar energy to synthesize carbohydrates by (b) . This process is described by the equation: H2O



CH2O

+

O2

energy + carbon dioxide + water  carbohydrates + oxygen

KNOW THIS

22. Label the chloroplast below with the terms: grana, stroma, and thylakoid thylakoid

grana stroma (fluid)

23. Many organisms carry on cellular respiration mitochondria CH2O

+

O2

which is performed within the . This process can be represented by the equation: (a)

(b)



CO2

+

H2O

+

chemical energy

carbohydrates + oxygen  carbon dioxide + water + ATP 24. Label the mitochondrion below with the terms: matrix and cristae

KNOW THIS

matrix (fluid)

cristae (folds)

25. Compare the chloroplast and the mitochondria in the following table. A. Organelle with a double membrane B. Converts solar energy into carbohydrates C. Converts carbohydrates into ATP D. Found in plant cells E. Found in animal cells F. Smaller of the two organelles G. Contain a single circular DNA molecule and ribosomes H. Divide by splitting in two (similar to how bacteria reproduce) I. Thought to play a role in aging J. All come from the female parent

Chloroplast X X X

X X

Mitochondria X X X X X X X X X

3.3

The Cytoskeleton

pages 77 - 80

26. The cytoskeleton is often compared with the bones animal. However, the cytoskeleton is dynamic components can assemble and disassemble

and muscles (c) , especially because its protein (d) as needed. (a)

(b)

of an

27. The cytoskeleton contains three types of proteins. Identify them in the image below.

intermediate filaments (width 8-11nm)

microtubules (width 25nm)

actin filaments (width 7nm) 28. Compare the functions of each of the cytoskeleton components.  Actin filaments (microfilaments): structural role (anchored to plasma membrane by special proteins) i. Interact with myosin motor molecules  Intermediate filaments: structural role, support nuclear envelope, support plasma membrane, form cell-to-cell junctions, mechanical strength  Microtubules: maintain cell shape, tracks for organelles to move along, form spindle near cell division i. Interact with kinesin and dynein motor molecules 29. What is the importance of the centrosome to cells? involved in microtubule assembly and disassembly, may organize mitotic spindle (form the MTOC = microtubule organizing center) 30. Complete the table below. Use Figures 3.13 and 3.14 to help. Centrioles Cilia & Flagella Microtubule pattern

9+0

9+2

Aids in cell division

Aids in movement

Cross-section drawing

Function

3.4

Plasma Membrane Structure & Function

pages 81 - 82

31. Draw a basic cross section of a portion of a plasma membrane. Label the following items: A. carbohydrate chain D. glycoprotein G. integral protein B. cholesterol E. hydrophilic head H. peripheral protein C. glycolipid F. hydrophobic tail I. phospholipid

A C

D

H phospholipid bilayer I

B

F E G

32. Match the following terms and descriptions. D carbohydrate chain A. associated with only one side of the plasma membrane C cholesterol B. span the membrane and can protrude from one or both sides F glycolipid C. regulates the fluidity of the membrane E glycoprotein D. can be attached to either the phospholipid heads or proteins B integral protein E. protein molecule with a carbohydrate chain attached A peripheral protein F. lipid molecule with a carbohydrates chain attached G phospholipid G. primary component of the plasma membrane 33. Describe why the structure of the plasma membrane is described as a fluid-mosaic model. “fluid” refers to the phospholipids and the “mosaic” refers to the proteins that are scattered throughout the membrane

34. Identify the FIVE types of integral proteins based on the diagrams below. Type: carrier Function: passage of molecules across membrane, often up a [ ] gradient (requires energy) Example: (1) sodium – potassium pump required for nerve conduction (2) movement of sugars

Type: receptor Function: allows specific molecules to bind causing protein to change shape and resulting in a cellular response Example: insulin receptors in liver causes storage of glucose

Type: cell recognition (also known as glycoprotein) Function: helps the body recognize its own cells versus foreign cells and pathogens (immune) Example: white blood cells keep body healthy

Type: enzymatic Function: carry out metabolic reactions directly (catalyze a specific reaction) Example: adenylate cyclase involved in ATP metabolism. Final steps of aerobic respiration.

Type: channel Function: passage of molecules across a membrane “freely” down a [ ] gradient (no energy) can be gated Example: H+ across inner mitochondria membrane to create ATP

3.5

The Permeability of the Plasma Membrane

pages 83 - 91

35. Why is the plasma membrane better referred to as selectively permeable rather than semi-permeable? The cell regulates the passage of molecules into and out of cell, “chooses” what goes across rather than allowing through only by size

36. Energy is NOT required to transport molecules across the plasma membrane if they are…  PASSIVE 

small, non-charged going down [ ] gradient from [high]  [low]

 Examples include: water, O2, CO2, some sugar and amino acids 37. Energy is required to transport molecules across the plasma membrane if they are…  large, charged ACTIVE  going up [ ] gradient from [low]  [high]  Examples include: macromolecules, sodium ions, glucose 38. While both involve movement from [high] to [low], what is the difference between diffusion and osmosis? Diffusion deals with all ions and molecules while osmosis deals only with water molecules

39. Compare the three states of tonicity that may affect a cell.

Prefix Meaning Net movement of water (in, out or at equilibrium)

Isotonic

Hypotonic

Hypertonic

the same as

less than

more than

at equilibrium

in

out

H2 O

H2 O

H2 O

Drawing of an animal cell in a solution of this type

40. Are the following terms or descriptions related to isotonic (I), hypotonic (HO), or hypertonic (HE) solutions? A. HE crenation B. HO cytolysis C. HO turgor pressure D. HE plasmolysis E. I 0.9% NaCl intravenous drip F. HE preserving meats by salting them G. HO keeping vegetables crisp by spraying them with distilled water

41. Biologically useful molecules are able to enter and exit the cell at a rapid rate because of carrier proteins in the membrane. These proteins are believed to undergo a change in shape that moves the molecule across the membrane. 42. Define the two categories of transport  facilitated: no energy required, uses mainly channel proteins and some carrier proteins, requires a [ ] gradient 

active: requires energy, gated channel proteins, carrier proteins, formation of vesicles

43. Why are proteins involved in active transport often called “pumps”? because they are pushing ions or molecules UP a [ ] gradient 44. Vesicles must be used to move macromolecules across the plasma membrane. The process of moving large (a) while the process of moving substances out of the cell is called exocytosis (b) substances into the cell is called endocytosis . 45. Name the three ways large substances can enter a cell. Then briefly describe the process in terms of an area of the body where it occurs, or what substances are brought in this way, etc. phagocytosis

pinocytosis

receptor mediated endocytosis

Description

Description

Description

“cell eating”

“cell drinking”

form of pinocytosis

Taking in large particles (e.g. worn out cells or bacterium) into a vesicle to fuse with a lysosome. Hydrolytic enzymes released to breakdown contents.

Small items (e.g. glucose) are taken in for use or transport. Happens continuously for cells (e.g. kidney filtering blood, intestines absorbing nutrients)

Very selective and more efficient. Uptake and exchange between cells (e.g. moving substances between mother and fetal blood at placenta)

Example: white blood cells

Edmodo Assignment! Read “Osmotic Balance in Salmon” article on page 89 and answer the questions below on Edmodo when asked to. 1. Define anadromous and smoltification. 2. Answer book question #2. 3. Describe in moderate detail what happens to a salmon as it returns to its natal stream to spawn. Chapter 3 Review Questions 1. 3. 4. 5. 6. 7. 8.

A D D D B C C

pages 102 – 107 9. D 10. B 11. D 12. C 13. D 15. D 16. C

17. A 18. C 19. D 20. C 21. A 22. C 23. A

31. Only one possible answer for each (a) IV 32. (a) VI (g) IX (m) IV

(b) I (h) III, VIII (n) VII

(b) V

(c) II (i) III, VIII (o) VIII

(c) VII (d) VI (j) IX (p) III, VIII

24. C 25. C 26. C 27. D 28. C 29. D 30. D

(d) III

(e) I

(e) V (k) IX

(f) V

(g) II

(f) VII (l) VI

35. cellulose 36. A 37. vesicle 38. maintain rigid structure, pushes against cell wall 40. Name all 3 CO2 + sunlight + H2O 45. Cardiac muscle cells need lots of energy which is supplied by the mitochondria Testes have smooth ER to produce testosterone 46. H2O2 would build up and be toxic to the cells and body 50. The bacterium would be brought inside a cell by phagocytosis into a vesicle. This would merge with a lysosome which would empty its digestive enzymes to break it down

51. The cell would shrivel and turgor pressure would decrease 52. Reverse processes: the products of one are the reactants of the other 57. The cell would divide or infold 58. Show your work 3:1 4:3 3:2

3÷1=3 4 ÷ 3 = 1.3 3 ÷ 2 = 1.5

*

_

60. Water is always entering the cells so organisms need to adapt a method to remove excess water (e.g. contractile vacuoles, dilute urine, etc) 61. Temperature, molecule size, polarity, [ ] 65. Hypotonic: 1 Hypertonic: 2 66. Chloroplasts pushed to the edges by the central vacuole 67. Water goes out 70. Plasmolysis 71. Water comes in, turgor pressure increases 72. Test tube 1 isotonic Test tube 2 hypertonic Test tube 3 hypotonic 73. Cell shrivels, water goes out, crenation 74. Water goes in, cell bursts, hemolysis 83. 4 and 5 84. about 15% 85. SA:V ratio is too large for efficient exchange of materials for an organism to survive * incorrect answer key, look at answer for #90 91. Weakened wall gives increased chance for viral infections or cell might burst with increased water intake

Mark the review questions using the answer key on pages 527 – 530 Extra practice (will not be marked). See how many of these organelles you know. Some are duplicated and there may be some that are hard to identify so just name as many as you can. A – cell membrane B – nuclear envelope C – nuclear pore D – nucleolus E – chromatin F – nucleoplasm G – mitochondria H – Golgi body I – centriole J – microtubules K - vesicle L – lysosomes M – vacuoles N – actin filaments O – ribosomes P – rough & smooth ER Q – cytoplasm