Period+4+Questions

Lysosome Golgi apparatus Rough ER Nucleus Mitochondrion** [5]
 * 1. State one function of...


 * 2. Describe how sexual reproduction results in genetic variation.** [4]

3. Describe, with the aid of a diagram, the behavior of chromosomes in the different phases of meiosis. **[5]** -interphase I- chromosomes, containing 2 identical sister chromatids, replicate but stay uncondensed; centrosomes replicate; -prophase I- chromosomes condense, homologous chromosomes pair up; crossing over, chiasmata are formed; spindle formed; nucleus broken down; this phase is 90% of meiosis -metaphase I- homologous pairs (tetrads) arranged on metaphase plate; microtuble attached to kinetochore -anaphase I- spindle moves homologous chromosomes toward opposite poles; sister chromatids remain intact -telophase I and cytokinesis- two haploid daughter cells formed; cleavage furrow or cell plate; sometimes followed by interphase II -prophase II- spindle apparatus formed -metaphase II- chromosomes aligned on metaphase plate; two sister chromatids are genetically different (due to crossing over) -anaphase II- centromeres separate and sister chromatids move towards opposite poles -telophase II and cytokensis- nuclei form; chromosomes decondense; four genetically different haploid daughter cells -//Elena//
 * -** see diagram page 244

-2 to the n possible combinations of chromosomes -random orientation of bivalents/pairs of chromosomes -maternal and paternal chromosomes could go to either pole -eg over 8 million in humans -crossing over of tetrads, Chiasmata -exchange of material between homologous chromosomes/non-sister chromatids -segregation of alleles in meiosis -combinations of alleles are broken up -fertilization brings together genes from 2 different parents -fertilization generates new combo of genes
 * 4. Explain how meiosis and fertilization can give rise to genetic variety.** [6]


 * 5. Describe how sexual reproduction promotes genetic variation within a species.** [4]


 * 6. Explain how meiosis results in great genetic variety among gametes.** [8]

Enzymes have catalytic activity that depends on the strand of amino acids at the active site. This strand of proteins is very sensitive to changes in the environment. Temperature increase can speed reactions at first, because it helps the reactants get to their activation energy. However, if temperature of the environment gets to be too high, the enzyme will denature, meaning that the active site will lose its substrate-specific shape and be unable to function. (So temperature makes enzyme activity increase, level off, and decrease) The same goes for if the environment's pH gets too acidic or too basic - enzymes are particular and only can operate at certain conditions. Substrate concentration is also important: the more substrates, the more enzymes can catalyze, to a point. There are only so many enzymes. (So substrate concentration increases enzyme activity and then it levels off)
 * 7. Explain the effects of temperature, pH, and substrate concentration on enzyme activity.** [8]

//- Shape of active site and substrare fit; they complement each other - Chemical properties of substrate and enzyme attract: opposite charges// //- Enzyme/active site is not rigid and substrate can induce slight change in shape////- Allows substrates of similar structure to bind with same enzyme////- Causes weakening of bonds in substrate to lower activation energy////- Lock and key model - Induced fit//
 * 8. Outline enzyme-substrate specificity.** [5]

The allosteric site of the enzyme is not the same as the active site. It controls the metabolic pathways by preventing the enzyme from converting a substrate to the next intermediate. Feedback inhibition is a type of non competitive inhibition where when there is an abundance of the product made by the enzyme, that end-product will bind to the allosteric site therefore causing the active site to change shape and not allow substrate to interact with the enzyme. (video: []) -Didas
 * 9. Explain how allosteric control of metabolic pathways by end-product inhibition includes negative feedback and non-competitive inhibition.** [8]

Arteries carry oxygenated blood at very high pressure through the body (right from the aorta), so they have to be able to transport a lot, quickly (before the oxygen diffuses out of the bloodstream). Because of this, arteries are small and thickly lined with muscle, which can contract in time with skeletal muscles to pump blood around. Veins, on the other hand, carry deoxygenated blood back to the heart, and they are not in so much of a hurry. Veins are large in diameter and pretty thin, but they still have muscle that helps blood flow to the heart. Both veins and arteries are equipped with strong one-way valves that prevent backflow. Both also have endothelial cells, smooth for easy blood flow, and basement membranes. Capillaries are really thin and consist only of endothelial cells and a basement membrane, which facilitates diffusion. There are huge networks of them so that the ratio of surface area to volume is really big (i.e. lots of diffusing going on).
 * 10. Explain the relationship between the structure and function of the arteries, veins, and capillaries.** [8]

- atria and ventricles are in diastole - blood returning from large veins flows into atria and ventricles - atrial systole forces remaining blood out of atria into ventricles - ventricular systole pumps blood into large arteries
 * 11. Explain the events of the cardiac cycle.** [7]

Ok so here’s what I found in the book: The SA node or pacemaker, sets the tempo of the heart beat by generating electrical signals that spread through both atria, making them contract simultaneously. The signals to contract are delayed at the AV nodes for about 0.1s, during which blood in the atria empties into the ventricles, specialized muscle fibers called bundle branches and purkinje fibers then conduct the signals to the apex of the heart and throughout the ventricular walls. The signals trigger powerful contractions of both ventricles from the apex toward the atria during driving blood into the large arteries. And here’s what the rubric said: Myogenic/initiated in heart muscle itself SA node/pacemaker sends waves of impulse to arteries; stimulus to AV node Conducting fibers/bundle of HIS/Purkinje fibers conduct impulses to lower ventricles Moderated by ANS/Vagus nerve/Parasympathic
 * 12. Describe the mechanisms that control the heartbeat.** [4]


 * 13. Draw and label a diagram t show the internal structure of the heart.** [6]


 * 14. Describe how carbon dioxide is carried by blood.** [4]


 * 15. Explain the process of aerobic respiration including oxidative phosphorylation.** [8]
 * After Glycolysis has occurred there is 2 molecules of pyruvate that enter the mitochondrion if oxygen is present (aerobic respiration).
 * Pyruvate enters the mitochondrion via active transport and it is converted into acetyl CoA is the junction between glycolysis and the Citric Acid Cycle/Krebs Cycle.
 * Pyruvate is broken down into three Carbon Dioxide molecules
 * The cycle generates 1 ATP per turn by substrate-level phosphorylation.
 * Most chemical energy is transferred to NAD+ and enzyme FAD during the redox reaction, the reduced coenzymes NADH and FADH2 go on to the ETC
 * For each turn of the cycle 2 CO2 enter in an acetyl group form(step1) two different carbons leave in an oxidized form, acetyl CoA joins the cycle by combining with oxaloacetate forming citrate. From steps 2-8 in the cycle decompose the citrate back to oxaloacetate.
 * Each acetyl group that enters cycle 3NAD+ are reduced to NADH (steps 3, 4, 8), electrons are transferred to FAD (step6), GTP is formed by substrate- level phosphorylation (step5) this produces an ATP molecule
 * Most of the ATP results form oxidative phosphorylation when NADH and FADH2 produced by the cycle relay the electrons into the ETC, this process supplies the necessary energy for the phosphorylation of ADP to ATP.


 * 16. Explain the similarities and differences in anaerobic and aerobic cellular respiration.** [8]


 * 17. Compare, with the aid of a diagram, the structure of generalized prokaryotic and eukaryotic animal cells.** [8]

-Lysosome - breaks down "stuff" in cell using hydrolytic enzymes -Golgi apparatus - The postal office of the cell, sends stuff where it needs to go. -Rough ER - Produces proteins -Nucleus - Contains and protects DNA -Mitochondrion - Produces ATP though the ETC. Big D
 * 18. State one function of each of the following organelles: lysosome, golgi apparatus** [2]


 * 19.

20. Discuss possible exceptions to the cell theory.** [4] //Cell Theory:// 1.All living things are made of cells. 2.Cells are the basic units of life. 3.Cells come only from other cells. -Tiny Okay, I looked up the last one, and apparently it's a slime mold (??), which starts life as an amoeba-like thing but then reproduces when it finds food and has all these nuclei floating around without any membranes in between them. They don't technically belong to the kingdom fungus, or really anything, and they produce with spores. I don't know how helpful that is, but there you go.
 * Viruses- a virus is not a cell viruses are made of two chemicals (protein & nucleic acid) but have no membranes, nucleus, or protoplasm. They appear to be alive when they reproduce after infecting a host cell.
 * Mitochondria & chloroplasts- These cell organelles have their own genetic material and reproduce independently from the rest of the cell.
 * Evolution of cells- If all cells come from other living cells then where did the first cell come from?
 * [ I can’t find the fourth exception any help? If no other exception then maybe we can list the cell theory.]

This is the actual rubric. I don't understand a few of these--like the receptor-mediation thing--but this is not a bad question. Just write all the facts you know about endocytosis. Also, Mr. Stickrath said you can describe the actual process in writing for all the points. -Sarah
 * 21. Outline the process of endocytosis.** [5]
 * the mechanism whereby cells take in solids and/or solutions
 * involves formation of vesicles
 * infolding of cell membrane
 * called phagocytotsis when solids/organisms are involved
 * phagocytosis is called feeding in some unicellular organisms
 * called pinocytosis when solutions are taken in
 * vesicles are much smaller in pinocytosis
 * requires energy/active processes
 * may be receptor-mediated (like HIV)
 * annotated diagram illustrating the process may be used to gain some or all of the points.

Phospholipids have tails made of fatty acids, both saturated and unsaturated. Unsaturated fatty acids have kinks in them, which allow for the maintenance of fluidity in the fluid mosaic model membrane. Both kinds of fatty acids are hydrophobic, resistant to water, whereas the heads are hydrophilic/polar, meaning they are able to exist in water. Phospholipids in a membrane are organized into a bilayer, with the hydrophobic parts facing inwards and the heads facing out into the cytoplasm or the environment, keeping the cell separate from its environment and maintaining only partial permeability of solutes into the cell.
 * 22. Explain how the structure and properties of phospholipids help to maintain the structure of cell membranes.**


 * 23. Describe the process of active transport.** [4]


 * 24. Draw diagrams to show the four stages of mitosis in an animal cell with four chromosomes.** [5]


 * 25. Draw a labeled diagram of the fluid mosaic model of the plasma membrane.** [5]

In order for passive diffusion to occur there must be a __concentration gradient__. Passive diffusion __moves "down" the gradient__ thus from high concentration to low concentration so it requires __NO ATP.__ Big molecules must travel through __integral proteins__ and __water moves by osmosis__. __Charged molecules more by route of facilitated diffusion across the membrane.__ (underlining represents rubric requirements)
 * 26. Describe passive transport across a biological membrane.** [5]

Right, lots of stuff here. Vesicles are used to transport pretty much everything around the cell. (1) They generally carry proteins from the rough ER to the golgi apparatus (1) and from the golgi apparatus to the plasma membrane (1). Vesicles are also used in taking food to lysosomes to be digested(1). They form by "pinching off" from a membrane (endocytosis)(1), making that membrane shorter (1). They are reabsorbed when they fuse with a membrane (exocytosis)(1), releasing their contents outside of it, and making that membrane longer (1). Phagocytosis and Pinocytosis also are ways of forming a vesicle (1). That's nine. You can get another point or so by giving a specific example. (Say, leukocytes use phagocytosis to form a vesicle with a pathogen in it, and then destroy it with hydrolytic enzymes). Big D
 * 27. Explain how vesicles are used in cells, including the way in which they form and are reabsorbed.** [8]


 * 28. Draw a diagram of the human digestive system.** [4]


 * 29. Describe the role of enzymes in the process of digestion of proteins, carbohydrates, and lipids in humans.** [6]

**-**salivary amilase is found in saliva that hydrolyzes starch and glycogen into smaller polysaccharides and maltose, which is a disaccharide. The optimum ph is 7. -pepsin is found in gastric juice, and it hydrolyzes proteins by breaking peptide bonds adjacent to specific amino acids, making proteins into smaller polypeptides. It works best at a ph of 2. -//Elena//
 * 30. State the source, substrate, products, and optimum pH for any two named digestive enzymes.** [4]


 * 31.

32.

33. Blood vessels carry blood to and from the kidney. Draw a labelled diagram to show the internal structure of the kidney, including the vessels that are connected to it.** [5]


 * 34. Compare the composition of blood arriving at the kidney wih the composition of blood carried away from it.** [4]


 * 35. Explain the control of anti diuretic hormone (ADH) secretion.** [6]

-Mouth/nose -trachea -bronchioles -lungs -alveoli -diaphram -ribs/intersoctal mebrane
 * 36. Draw a diagram of the human gas exchange system.**


 * 37. Explain how and why the breathing rate varies with exercise.** [9]


 * 38. Explain the way the body acclimatizes to gas exchange at high altitudes. [3]

39. Explain how the light-independent reactions of photosynthesis rely on light-dependent reactions.

40. Outline the effect of temperature, light intensity, and CO2 concentration on the rate of photosynthesis.** [6]


 * 41. Explain the reactions involving the use of light energy that occur in the thylakoids of the chloroplast.** [8]


 * 42.

43.

44.

45.**