Chapter 7 OBJECTIVES
After reading this chapter and attending lecture, the student should be able to:
- Distinguish between prokaryotic and eukaryotic cells.
Prokaryotic cell are the simplest form of DNA and have no nucleus. They are only found in bacteria. Eukaryotic cells on the other hand are more complex, do have a nucleus and are found in animals and plants.
- Describe the structure and function of the nucleus, and briefly explain how the nucleus controls protein synthesis in the cytoplasm.
Nucleus is a generally conspicuous membrane-bound cellular organelle in a eukaryotic cell; contains most of the genes that control the entire cell.
- Describe the structure and function of a eukaryotic ribosome.
A cytoplasmic organelle that is the site for protein synthesis
- List the components of the endomembrane system, describe their structures and functions and summarize the relationships among them.
The endomembrane system includes:
• Nuclear envelope
• Endoplasmic reticulum
• Golgi apparatus
• Lysosomes
• Vacuoles
• Plasma membrane (not actually an endomembrane, but related t o
endomembrane system)
Components of the endomembrane system are related through direct contact or
through vesicles
- Describe the vacuole & list types of vacuoles
A membrane-enclosed sac taking up more of the interior of a mature plant cell and containing variety of substances important in plant reproduction, growth and development. The three types are food vacuole, contractile vacuole and central vacuole.
- Explain the role of peroxisomes in eukaryotic cells.
Membrane-bound organelles that contain specialized teams of enzymes for specific metabolic pathways; all contain peroxide-producing oxidases.
- Describe the structure & function of a mitochondrion
A mitochondrion is an organelle in eukaryotic cell that serves as a site of regular respiration.
- Identify the three functional compartments of a chloroplast
Intermembrane space, Thylakoid space and Stroma.
- Describe probable functions of the cytoskeleton.
Provides structural support to the cells for cell motility and regulation.
- Describe the structure, monomers and functions of microtubules, microfilaments and intermediate filaments.
Are straight hollow fibers about 25 nm in diameter and 200 nm – 25 þm in length. Constructed from globular proteins called tubulin that consists of one þ-tubulin
and one þ-tubulin molecule. Functions include Cellular support; these microtubule function as compression-resistant girders to reinforce cell shape. Tracks for organelle movement (see Campbell, Figure 7.21). Protein motor molecules (e.g., kinesin) interact with microtubules to translocate organelles (e.g., vesicles from the Golgi to the plasma membrane). Separation of chromosomes during cell division
- Explain how the ultrastructure of cilia and flagella relates to their function.
The unique ultrastructure of cilia and flagella is necessary for them to function:
Sidearms are made of dynein, a large protein motor molecule that changes its conformation in the presence of ATP as an energy source. A complex cycle of movements caused by dynein's conformational changes, makes the cilium or flagellum bend (see Campbell, Figure 7.25). In cilia and flagella, linear displacement of dynein sidearms is translated into a bending by the resistance of the radial spokes. Working against this resistance, the "dynein-walking" distorts the microtubules, causing them to bend.
- Describe the structure of intercellular junctions found in plant and animal cells, and relate their structure to function.
Intercellular junctions help integrate cells into higher levels of structure and function.
Chapter 8 OBJECTIVES
- Describe the function of the plasma membrane.
The plasma membrane is the boundary that separates the living cell from its nonliving surroundings. It makes life possible by its ability to discriminate in its chemical exchanges with the environment.
- Explain how hydrophobic interactions determine membrane structure and function.
Hydrophilic portions of both proteins and phospholipids are maximally exposed to water resulting in a stable membrane structure.
- Describe how proteins are spatially arranged in the cell membrane and how they contribute to membrane function.
A specific protein speed movement of a solute across a membrane downs its concentration gradient.
- Describe factors that affect selective permeability of membranes.
Selective permeability of membrane allows only specific substances to pass. The factor that affects this is the plasma membrane.
- Define diffusion; explain what causes it and why it is a spontaneous process.
Diffusion is the movement of any molecules from an area of high concentration to an area of low concentration.
- Explain what regulates the rate of passive transport.
Proteins.
- Define osmosis and predict the direction of water movement based upon differences in solute concentration.
Osmosis is the movement of water molecules from an area of high concentration to an area of low concentration. If it goes from more concentrated to a less concentrated then it is called hypertonic. If is the other way around then is hypotonic. If the two are equal then is isotonic.
- Describe how living cells with and without walls regulate water balance.
Cell survival depends on balancing water uptake and loss
- Describe one model for facilitated diffusion.
- Explain how active transport differs from diffusion.
Active transport is the opposite of diffusion because it goes from a low concentration area to a high concentration area. Active transport also requires energy which diffusion doesn’t.
- Explain how large molecules are transported across the cell membrane.
Large molecules enter cells within vesicles pinched inward from the plasma membrane.
- Give an example of receptor-mediated endocytosis.
Chapter 12 OBJECTIVES
- Overview the major events of cell division that enable the genome of one cell to be passed on to two daughter cells.
Know from slide 12.3 of powerpoint
- Describe how chromosome number changes throughout the human life cycle.
Chromosomes number changes through the human life cycle as they reproduce. We are suppose to have 46 chromosomes. The division of chromosomes is abnormal then there will be a problem such as cancer.
- List the phases of the cell cycle and describe the sequence of events that occurs during each phase.
Mitosis: Division of the nucleus
Cytokinesis: Division of the cytoplasm
- List the phases of mitosis and describe the events characteristic of each phase.
Prophase, Metaphase, Anaphase, Telophase
Prophase: The nucleoli disappear and the chromatin condenses into chromosomes. The nuclear envelope breaks down and the mitotic spindle is assembled.
Metaphase: The chromosomes are distributed across the metaphase plate. Metaphase ends when the microtubules pull each chromosome apart into two chromatids.
Anaphase: Microtubules connected to the chromatids shorten, effectively pulling the chromosomes to the opposite poles.
Telophase: A nuclear envelope develops around each pole, forming two nuclei. Simultaneously, cytokinesis occurs, dividing the cytoplasm into two cells.
- Recognize the phases of mitosis from diagrams or micrographs.
Know from the power point slides
- Compare cytokinesis in animals and plants.
Is different because in the animal cell is more noticeable that in the plant cell. See slide of power point.
- Describe the process of binary fission in bacteria and how this process may have evolved to mitosis in eukaryotes.
Binary fission is the cell division in bacteria. The process starts with the duplication of the chromosomes. Then the continuous growth of the cells and last the cell division of occurs.
- Explain how abnormal cell division of cancerous cells differs from normal cell division.
They have abnormal growth and cancerous cells are immortals