Download Unit 2

Chapter 7
A TOUR OF THE CELL
OBJECTIVES
1. Distinguish between prokaryotic and eukariotic cells.
The prokaryotic cell has no nucleus, there is no membrane to separate the DNA from the rest of the cell.
The eukariotic cell has its nucleus which is enclosed in the nucleus envelope. The entire region between the
nucleus and the cell is the cytoplasm.
4. Describe the structure and function of the nucleus, and briefly explain how the nucleus controls protein
synthesis in the cytoplasm.
The nucleus controls most of the genes that control the cell.
Within the nucleus is chromatin, consisting of DNA and protein.
Figure 7.9 pg. 119
5. Describe the structure and function of a eukariotic ribosome.
Ribosomes build proteins in two cytoplasmic locales;
Free ribosomes are suspended in the cytosol.
Bound ribosomes are attached to the outside of a membranous network called the endoplasmic reticulum.
Figure 7.10 pg. 120
6. List the components of the endomembrane system, describe their structures and functions and summarize
the relationships among them.
Nuclear envelope- Figure 7.9 pg. 119
Endoplasmic reticulum- Figure 7.11 pg. 121
Golgi apparatus- Figure 7.12 pg. 122
Lysosomes- Figure 7.13 pg. 123
Vacuoles;
-food vacuoles- Figure 7.14 pg. 124
-contractile vacuoles-pump excess water out of the cell
-central vacuoles- Figure 7.15 pg. 125
Plasma membrane- Figure 7.6 pg. 115
7. Describe the vacuole & list types of vacuoles.
Vacuoles are membrane-enclosed sacs within the cell
Rest is previously mentioned
8. Explain the role of peroxysomes in eukaryotic cells.
Figure 7.17 pg. 126
The pheroxysome is a specialized metabolic compartment bounded by a single membrane.
Peroxysomes contain enzymes that transfer hydrogen from various substances to oxygen, producing
hydrogen peroxide as a by-product.
9. Describe the structure and function of a mitochondrion.
Figure 7.18pg 127
Site of cellular respiration; makes ATP
11. Identify the three functional compartments of a chloroplast.
Figure 7.19 pg. 127
12. Describe the probable functions of the cytoskeleton.
Figure 7.20 pg. 128
13. describe the structure, monomers and functions of microtubules, microfilaments and intermediate
filaments.
Table 7.2 pg. 129
14. Explain how the ultrastructure of cilia and flagela relates to their function.
Figure 7.24 pg. 132
17. Describe the structure of intercellular junctions found in plant and animal cells, and relate their
structure to function.
Figure 7.28 pg. 135
Figure 7.30 pg. 136
CHAPTER 8
MEMBRANE STRUCTURE AND FUNCTION
OBJECTIVES
1. Describe the function of the plasma membrane.
The plasma membrane controls traffic in and out of the cell it surrounds.
It has selective permeability, allowing some substances to cross.
5. Describe the fluid properties of the cell membrane and explain how membrane fluidity is influenced by
membrane composition.
A membrane is held together by hydrophobic interactions.
Figure 8.3 pg. 144
6. Explain how hydrophobic interactions determine membrane structure and function.
Figure 8.1 pg. 141
7. Describe how proteins are spatially arranged in the cell membrane and how they contribute to membrane
functions.
Figure 8.6 pg. 146
8. Describe factors that affect selective permeability of membranes.
The hydrophobic core of the membrane impedes the transport of ions and polar molecules, which are
hydrophilic. Very small molecules that are polar but uncharged can also pass through the membrane. The
lipid bilayer is not very permeable to larger, uncharged polar molecules.
9. Define diffusion; explain what causes it and why it is a spontaneous process.
Diffusion, the tendency for molecules of any substance to spread into the available space.
Rule of diffusion: A substance will diffuse from where it is more concentrated to where it is less
concentrated.
Figure 8.8 pg. 148
10. Explain what regulates the rate of passive transport.
The concentration gradient regulates passive transport.
Membrane permeability regulates the rate of passive transport.
11. Explain why a concentration gradient across a membrane represents potential energy.
12. Define osmosis and predict the direction of water movement based upon differences in solute
concentration.
Osmosis is the diffusion of water across a selectively permeable membrane.
Figure 8.9 pg 149
14. Describe how cell with and without walls regulate water balance.
Figure 8.10 pg 149
16. Describe one model for facilitated diffusion.
Figure 8.12 pg 151
17. Explain how active transport differs from diffusion.
In active transport molecules are pumped against their gradient, making the cell spend its own energy.
Figure 8.14 pg 153
20. Explain how large molecules are transported across the cell membrane.
Figure 8.17 pg 154
21. Give an example of receptor mediated endocytosis.
Human cells use cholesterol as a precursor for other steroids.
CHAPTER 12
THE CELL CYCLE
OBJECTIVES
2. Overview the major events of cell division that enable the genome of one cell to be passed onto two
daughter cells.
Cell division involves the distribution of identical genetic material-DNA-to the two daughter cells.
A cell preparing to divide first copies all its genes, allocates them equally to opposite ends of the cell, and
then separates into two daughter cells.
3. Describe how chromosome number changes throughout the human life cycle.
There are 46 chromosomes in the human stomatic cell. Reproductive cells or gametes have half as many
chromosomes as do stomatic cells, that is 23 chromosomes.
4. List the phases of the cell cycle and describe the sequence of events that occurs during each phase.
Figure 11.5 pg 207
5. List the phases of mitosis and describe the events characteristic of each phase.
Figure 11.6 pg 208
6. Recognize the phases of mitosis from diagrams or micrographs.
Figure 11.6 pg 208
8. Describe what characteristic changes occur in the spindle aparatus during each phase of mitosis.
Figure 11.6 pg 208
10. Compare cytokinesis in animals and plants.
Figure 11.9 pg 212
11. Describe the process of binary fission in bacteria and how this process may have evolved to mitosis in
eukaryotes.
Figure 11.2 pg 205
14. Explain how abnormal cell division of cancerous cells differs from normal cell division.
Figure 11.14 pg 218