1. Cellular Structure and Function
Chapter 7
Cellular Structure and Function

2. The Cell Theory All organisms are composed of one or more cells
The cell is the basic unit of structure and organization of organisms.
All cells come from preexisting cells.

3. Advent of the Cell Hooke and Leeuwenhoek used early microscopes
Hooke saw/named “cells” in dead cork
Leeuwenhoek saw living cells in pond water

4. Light Microscopes Use 1 or more lenses and visible light
Can view live specimens
Max 2000x due to poor resolution

5. Electron Microscopes Uses electrons instead of light for image
Very high power/resolution ( max 2 million X)
Specimen prep is deadly
SEM = Scanning, 3d surface image
TEM = Transmission, 2d, more powerful, view slice
Microscopy Links
9560x

6. Cell Types Prokaryotes Eukaryotes Simple (small) More complex (larger)
Plasma membrane
Cytosol
Non-membrane bound organelles
No membrane bound organelles
More complex (larger)
Plasma membrane
Cytosol
Non-membrane bound organelles
Has membrane bound organelles
Nucleus

7. Plasma Membrane Cell boundary (inside vs. environment)
Phospholipid Bilayer
Selectively permeable
Controls what/how much can enter or leave cell
Allows waste out/nutrients in

8. Phospholipid Bilayer Phospholipid structure
2 layers, tails facing each other
Glycerol + phosphate polar “Head”
2 nonpolar fatty acid tails (sat or unsat)

9. The Fluid Mosaic Model Phospholipid flow
Other molecules float on/with lipids
Proteins
Carbs
Cholesterol

10. Membrane Proteins
Signal transmission
Transport
Support

11. Membrane Carbohydrates
Attached to protein or lipid
Convey signals/communication

12. Membrane Cholesterol Embedded into phospholipids
Increase membrane fluidity
Especially in low/high heat
Unsat fat also helps with low temp

13. Cell Structures and Organelles
Animal Cell
Plant Cell
Cellular Pursuit

14. 7.3 Structures and Organelles

15. 7.3 Structures and Organelles

16. Outer Cell Structures Cell Membrane Cell Wall All cells have it
Flexible Phospholipid bilayer w/proteins
Selectively permeable (controls in/out)
Cell Wall
Not found in animal cells
Inflexible barrier for cell protection and support

17. Outer Structures Cont. Flagella Cilia
Long whiplike projections on some cells
Used for movement or feeding
Cilia
Small numerous cell projections on some cells

18. Some other major structures
Nucleus
Enclosed by double membrane nuclear envelope
Envelope has pores for transport
Contains DNA and nucleoli
Ribosomes
Protein synthesis
Made by nucleoli
No membrane (all cells have them)

19. Energy Organelles Mitochondria Chloroplast In all eukaryotic cells
Site of cell respiration (ATP production, Energy!)
Has folded inner membrane
Chloroplast
Only in Plant/algae cells
Site of photosynthesis (organic molecule creation)
Has lots of small sacs stacked inside

20. A Cell Framework Cytoskeleton Centrosome/Centrioles Protein skeleton
Provides structure, support, transport
Centrosome/Centrioles
microtubule production (ex. cell reproduction)
Centrioles only in animal cells

21. Endomembrane System Endoplasmic Reticulum (ER) Golgi Apparatus
Highly folded membranes
Smooth ER: lipid synthesis
Rough ER (w/ribosomes): protein synthesis
Transport and detox
Golgi Apparatus
Flattened stack of membranes
Modifies, packages, export proteins

22. Endomembrane System II
Vacuoles
Membrane bound storage vesicles
Reduced or not present in animal cells
Very large central vacuole in plants
Lysosomes
Membrane bound digestive vesicle
Contain enzymes
Usually only in animal cells

25. Cellular Transport Passive Transport (uses no Energy) Diffusion
Osmosis
Facilitated Diffusion

26. Diffusion Move from high to low conc. “Down” the conc. Gradient
Affected by temp, pressure, conc.
Dynamic Equilibrium = no net movement
Initial Conditions
Diffusion
Low
High
High
Low

27. Osmosis Diffusion of water across membrane Water is bound by solutes
More solute = less water
Water moves from low solute to high solute
Solutes suck

28. Osmosis II Three osmotic conditions
Isotonic: equal solute/water, no net movement
Hypertonic: more solute (water enters)
Hypotonic: less solute (water leaves)
Pay attention to frame of reference
Ex. The aquarium fish cells are hypertonic to the water can also be the aquarium water is hypotonic to the fish cells

29. Osmosis III
You find yourself stranded in a ship at sea. There is no rescue in sight, and you’ve already eaten Ra (2 hours after being stranded). Should you drink the seawater or go without water?
The zombie invasion has begun. You avoid Luckee (smart move, even if she’s not a zombie) by ducking into a bathroom. Is it a good idea to sleep in the bathtub full of water (assuming you won’t drown)?

30. Facilitated Diffusion
Diffusion through a membrane protein
Effects molecules unable to pass through membrane without help:
Larger and polar
Charged (ions)

31. Diffusion in a Cell

32. Channel Proteins
Carrier Proteins

33. Active Transport All move from low to high conc. All use Energy (ATP)
3 types:
Protein pumps
Endocytosis
Exocytosis

34. Sodium Potassium Pump Sample protein pump
Pumps 3 Na+ out of cell; 2 K+ into cell
Uses ATP, makes electrochemical gradient
Gradient of charge and chemicals

35. Endo/Exocytosis Endocytosis: Exocytosis
Ingest large molecules or small cells
Envelope particles with cell membrane
Exocytosis
Release large molecules/waste
Merge vesicle with cell membrane

36. 7.1 Formative Questions
Robert Hooke and Anton van Leeuwenhoek designed microscopes that enabled them to see organelles within the cells they observed.
true
false A B
FQ 1

37. transmission electron microscope scanning electron microscope
7.1 Formative Questions
Which type of electron microscope directs electrons over the surface of a nonliving specimen, producing a three-dimensional image?
transmission electron microscope
scanning electron microscope
scanning tunneling electron microscope
atomic force microscope A B C D
FQ 2

38. All cells, whether eukaryotic or prokaryotic, have a plasma membrane.
7.1 Formative Questions
All cells, whether eukaryotic or prokaryotic, have a plasma membrane.
true
false A B
FQ 3

39. What feature of eukaryotic cells has enabled
7.1 Formative Questions
What feature of eukaryotic cells has enabled
them to develop more specific functions than
prokaryotic cells?
nucleus
organelles
genetic material (DNA)
larger cell size A B C D
FQ 4

40. Which term describes the function of proteins
7.2 Formative Questions
Which term describes the function of proteins
found on the outer surface of the plasma
membrane?
identifiers
receptors
supporters
transporters A B C D
FQ 5

41. Which component of the plasma membrane
7.2 Formative Questions
Which component of the plasma membrane
contributes to the fluidity of the plasma
membrane?
phospholipids
proteins
carbohydrates
cholesterol molecules A B C D
FQ 6

42. What is the function of carbohydrates that
7.2 Formative Questions
What is the function of carbohydrates that
stick out from the outer surface of the plasma
membrane?
They give the cell shape and enable it to move.
They give the plasma membrane fluidity.
They help the cell identify chemical signals.
They hold the cell in place. A B C D
FQ 7

43. In prokaryotic cells, where does the conversion
7.3 Formative Questions
In prokaryotic cells, where does the conversion
of fuel particles into usable energy occur?
cytoplasm
DNA
mitochondria
ribosomes A B C D
FQ 8

44. Which organelle is similar to the section of a
7.3 Formative Questions
Which organelle is similar to the section of a
factory that organizes, boxes, and ships the
final product?
chloroplast
endoplasmic reticulum
Golgi apparatus
mitochondrion A B C D
FQ 9

45. In which structure is light energy captured and
7.3 Formative Questions
In which structure is light energy captured and
converted to chemical energy?
chloroplast
lysosome
nucleus
vacuole A B C D
FQ 10

46. Which type of cellular transport does not require an input of energy?
7.4 Formative Questions
Which type of cellular transport does not
require an input of energy?
active transport
endocytosis
exocytosis
facilitated diffusion A B C D
FQ 11

47. Sugar moves to the right. Water moves to the left.
7.4 Formative Questions
How does osmosis occur between the two solutions separated by the selectively permeable membrane?
Sugar moves to the left.
Sugar moves to the right.
Water moves to the left.
Water moves to the right. A B C D
FQ 12

48. Which diagram shows a cell in a hypotonic solution?
7.4 Formative Questions
Which diagram shows a cell in a hypotonic solution? A. B. C. A B C
FQ 13

49. Compare and contrast plant and animal cells.
Chapter 7
Cellular Structure and Function
Chapter Assessment Questions
Compare and contrast plant and animal cells.
Answer: Plant cells have both cell walls and
chloroplasts. Animal cells do not have
these structures. Only animal cells contain
lysosomes. Both plant and animal cells
have plasma membranes, a nucleus,
mitochondria, vacuoles, endoplasmic
reticulum, Golgi apparatus, centrioles, a
nucleolus, ribosomes, and a cytoskeleton.
CAQ 1

50. Identify the structure represented by this image.
Chapter 7
Cellular Structure and Function
Chapter Assessment Questions
Identify the structure represented by this image.
Answer: plasma membrane and phospholipid
bilayer
CAQ 2

51. If you wanted to see a detailed 3-dimensional
Chapter Diagnostic Questions
If you wanted to see a detailed 3-dimensional
image of a cell, which type of microscope would you use?
scanning electron microscope
transmission electron microscope
scanning tunneling microscope
simple light microscope A B C D
CDQ 1

52. Which is not a part of the cell theory?
Chapter Diagnostic Questions
Which is not a part of the cell theory?
Cells are the basic unit of structure and organization of all living things.
All living things are composed of one or more cells.
Cells arise only from previously existing cells.
Cells are produced spontaneously as an organism grows. A B C D
CDQ 2

53. Which cell organelles are directly involved with
Chapter Diagnostic Questions
Which cell organelles are directly involved with
the production of proteins?
ribosomes, endoplasmic reticulum, nucleus
cell membrane, lysosome, Golgi apparatus
nucleus, centriole, vacuole
endoplasmic reticulum, cilia, mitochondrion A B C D
CDQ 3

54. _______ is the net movement of particles from
Chapter Assessment Questions
_______ is the net movement of particles from
an area where there are many particles of the
substance to an area where there are fewer
particles of the substance.
Diffusion
Endocytosis
Exocytosis
Equilibrium A B C D
CAQ 3

55. What is the magnification of a compound light
Standardized Test Practice
What is the magnification of a compound light
microscope that uses a 10X lens in series with
a 25X lens?
2.5X
25X
35X
250X A B C D
STP 1

56. What part of the plasma membrane makes it
Standardized Test Practice
What part of the plasma membrane makes it
difficult for water-soluble substances to move
freely into and out of the cell?
membrane proteins
transport proteins
the nonpolar tails in the middle of the plasma membrane
the polar heads facing the inside and outside of the cell A B C D
STP 2

57. Muscle cells require a great amount of energy.
Standardized Test Practice
Muscle cells require a great amount of energy.
Which would you expect to find in large
numbers in muscle cells?
centrioles
endoplasmic reticulum
mitochondria
ribosomes A B C D
STP 3

58. In what type of cell would you most likely
Standardized Test Practice
In what type of cell would you most likely
expect to find numerous lysosomes?
a plant cell that stores food, enzymes, or other materials
a plant cell that uses light energy for photosynthesis
a single-celled organism that moves around its environment
a white blood cell that digests bacteria and viruses A B C D
STP 4

59. Standardized Test Practice
Why are the carrier proteins that move substances across a plasma membrane from a region of higher concentration to a region of lower concentration called pumps?
They require energy to move substances against a concentration gradient.
They open and close to allow substances to diffuse across the plasma membrane.
They help with the osmosis of water through the plasma membrane.
They pump water into the cell, causing the pressure within the cell to increase. A B C D
STP 5