nucleus disintegration,

Hormonal signaling is important between cells that are at greater distances apart than in synaptic signaling. C) Both act on target cells by a G-protein-signaling pathway. D) Only A and B are true. E) A , B, and C are true. 3. From the perspective of the cell receiving the message, the three stages of cell signaling are A) the paracrine, local, and synaptic stages. B) signal reception, signal transduction, and cellular response C) signal reception, nucleus disintegration, and new cell generation. D) the alpha, beta, and gamma stages. E) signal reception, cellular response, and cell division. 4.

When a cell releases a signal molecule into the environment and a number of cells in the immediate vicinity respond, this type of signaling is A) typical of hormones. B) autocrine signaling. C) paracrine signaling. D) endocrine signaling. E) synaptic signaling. 5. The yield from putting NADH + H+ through the electron transport chain is ________ ATP and the yield from FADH2 is ________ ATP. A. three, two B. three, four C. four, three D. two, three 6. Fermentation takes place in the ________ of oxygen, a process also known as ________ respiration. A. presence, aerobic B. presence, anaerobic C. absence, aerobic

D. absence, anaerobic 7. Pyruvate is the starting compound for ________. A. Alcohol fermentation B. Glycolysis C. Lactic acid fermentation D. All of the answers are correct E. Alcohol fermentation and lactic acid fermentation 8. ________ is the key regulatory enzyme of the glycolytic pathway. A. Hexokinase B. Rubisco C. Phosphofructokinase D. Isomerase 9. What is the role of O2 in electron transport? final electron acceptor 10. What are the three stages of cellular respiration and which one contributes most to ATP yield? Glycolysis, the citric acid cycle and oxidative phosphorylation/electron transport.

Oxidative phosphorylation contributes most. 11. Describe the importance of the membrane in electron transport. Provides a ‘substrate’ for the proteins involved; support, positioning relative to each other, etc. Provides a barrier across which protons can be pumped to form a gradient that is later used to form ATP. 12. What pathway is common to both aerobic and anaerobic respiration? Glycolysis 13. What is the key regulatory enzyme of glycolysis and what is the effect of an increased ATP concentration on this enzyme and on respiration in general? The key regulatory enzyme of glycolysis is phosphofructokinase.

An increase in ATP concentration means that the cell is not using all the energy that is being produced from the breakdown of glucose. Therefore, phosphofructokinase is shut down to prevent unnecessary breakdown of energy stores (i. e. glucose). Respiration will slow down. 14. What is the primary difference (in general terms) between substrate-level phosphorylation and oxidative phosphorylation? substrate-level phosphorylation involves the transfer of a phosphate group from one molecule to another and oxidative phosphorylation involves the formation of ATP as a result of redox reactions in the electron transport chain. 5. What is the name of the enzyme that uses the proton gradient to make ATP? Answer: ATP synthase Objective 2-4 16. A type of local regulation in which only the adjacent cells are affected by signal chemicals is called ________ signaling. a. paracrine b. hormone c. autosomal d. neuronal 17. A type of receptor which uses GTP to activate a mobile peripheral protein is called a: ________. e. receptor-tyrosine kinase f. G-protein-linked receptor g. ligand-gated ion channel 18. When a signal molecule binds to ________, the receptor forms a dimer and then has the ability to phosphorylate several different proteins. h. eceptor-tyrosine kinase i. G-protein-linked receptor j. ligand-gated ion channel 19. A(n) ________ is a small, non-protein molecule that functions in a transduction pathway. k. hydrolase l. enzyme m. second messenger 20. ________ is a second messenger that is actively pumped out of the cytosol, which keeps the concentration low. Then, when the second messenger is released, it may have a large effect on several proteins simultaneously. n. cAMP o. Ca2+ p. IP3 q. DAG 21. Different types of cells may respond differently to the same signal molecule because ___________. r. the signal molecule emits different wavelengths of light s. ach type of cell has its own complement of proteins t. the cell may feel threatened by the signal 22. Explain why hormones are not considered local regulators. By definition, hormones act on parts of the body that are distant from the site of production of the hormone. 23. Describe how signal amplification is accomplished in target cells. For each signal molecule, many primary messengers are activated, and for every level of the series of reactions that results, many new reactions are stimulated. 24. What are the three stages of cell signaling? Reception, transduction, response. 25.

Describe where receptors for water-soluble and lipid soluble signal molecules are located. For example, receptors for ________ signal molecules are typically on the exterior of the plasma membrane. water-soluble, on the exterior of the plasma membrane; lipid-soluble, inside the cell. 26. What are the two main advantages of using a multistep pathway in the transduction stage of cell signaling? signal amplification and regulation/control 27. Compare kinases and phosphatases in terms of phosphorylation. kinases phosphorylate another molecule; phosphatases dephosphorylate another molecule. Objective 2-5 ) The centromere is a region in which A) chromatids are attached to one another. B) metaphase chromosomes become aligned. C) chromosomes are grouped during telophase. D) the nucleus is located prior to mitosis. E) new spindle microtubules form. 2) What is a chromatid? A) a chromosome in G1 of the cell cycle B) a replicated chromosome C) a chromosome found outside the nucleus D) a special region that holds two centromeres together E) another name for the chromosomes found in genetics 3) What is the name for the special region on a duplicated chromosome that holds the sister chromatids together? A) centrosome B) centromere

C) kinetochore D) desmosome E) microtubule organizer region 4. How is the S phase of the cell cycle measured? A) counting the number of cells produced per hour B) determining the length of time during which DNA synthesis occurred in the cells C) comparing the synthesis versus the breakdown of S protein D) determining when the S chromosome is synthesized E) stopping G1 and measuring the number of picograms of DNA per cell 5. Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with A) a single large nucleus. B) high concentrations of actin and myosin.

C) two abnormally small nuclei. D) two nuclei. E) two nuclei but with half the amount of DNA. 6) Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants A) the spindles contain microfibrils in addition to microtubules, whereas animal spindles do not contain microfibrils. B) sister chromatids are identical, but they differ from one another in animals. C) a cell plate begins to form at telophase, whereas animals a cleavage furrow is initiated at that stage. D) chromosomes become attached to the spindle at prophase, whereas in animals chromosomes do not become attached until anaphase.

E) spindle poles contain centrioles, whereas spindle poles in animals do not. 7) The correct sequence of steps in the M phase of the cell cycle is A) prophase, prometaphase, metaphase, anaphase, telophase. B) prophase, metaphase, prometaphase, anaphase, telophase. C) prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis D) prophase, metaphase, anaphase, telophase, cytokinesis. E) cytokinesis, telophase, prophase, prometaphase, metaphase, anaphase. 8. Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible.

In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis? A) telophase B) prophase C) anaphase D) metaphase E) prometaphase 9. The questions below consist of five phrases or sentences concerned with the cell cycle. For each one, select the answer below that is most closely related to it. Each answer may be used once, more than once, or not at all. A. G0 B. G1 C. S D. G2 E. M 9. the shortest part of the cell cycle Answer: E 10. What is the name of enzymes that control the activities of other proteins by phosphorylating them? A) ATPases B) kinases

C) cyclins D) chromatin E) protein kinases 28. Interphase includes _______. u. Mitosis (M) v. Gap 1 (G1) w. Synthesis (S) x. all of the answers are correct y. both Gap 1 (G1) and Synthesis (S) 29. During ________, we can see highly condensed chromosomes in no particular pattern, but during ________ the highly condensed chromosomes are lined up across the middle of the cell. z. anaphase, telophase {. metaphase, anaphase |. prometaphase, metaphase }. metaphase, prophase 30. ________ attach at the centromeres of each sister chromatid in preparation for nuclear division. ~. centrosomes . kinetechore microtubules . nonkinetechore microtubules asters . centrioles 31. ________ duplicate during G2 of interphase, and then move to opposite ends of the cell. They are known as the microtubule organizing centers and microtubules radiate out from them. . centrosomes . kinetechore microtubules . nonkinetechore microtubules . asters . centrioles 32. ________ content in the cell fluctuates in a regular manner. As it accumulates, more of it binds with ________ to form MPF. This signals the cell to begin cell division. . Cdk, Cyclin . Cyclin, Cdk . Cyclin, phosphofructokinase 33. What is metastasis? Answer: The spread of cancer cells to locations distant from their original site.