AP Bio Unit 2 Review Shee1

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AP Bio Unit 2 Review Sheet VOCAB 1. Cytoskeleton - a network of microtubules, microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve a variety of mechanical, transport, and signaling functions; provides structural support to the cells for cell motility and regulation; mechanical support to cell, helps cell maintain its shape 2. Tight junctions - fusion of adjacent cell membrane, prevents leakage between cells 3. Desmosome - anchoring junction w/ intermediate filaments cementing adjacent cells together 4. Plasmodesma - (plasmodesmata) an open channel in the cell wall of a plant through which strands of cytosol connect from an adjacent cell; allows cytoplasm of one cell to be continuous w/ cytoplasm of neighboring cell 5. Hypotonic - a solution w/ a lower solute concentration compared to that inside a cell 6. Hypertonic - a solution w/ a greater solute concentration than that inside a cell 7. Isotonic - a solution w/ an equal solute concentration compared to that inside a cell 8. Plasmolysis - phenomenon where a walled cell shrivels and the plasma membrane pulls away from the cell wall as the cell loses water to a hypertonic environment 9. Endocytosis - extracellular substances are incorporated into the cell in vesicles by an inward budding of the plasma membrane; forms a food vacuole 10. Exocytosis - vesicles fuse with the plasma membrane and dump their contents to the outside of the cell; cellular secretion of biological molecules 11. Receptor-mediated endocytosis - the process of importing specific macromolecules into the cell by the inward budding of vesicles form from coated pits; occurs in the response to the binding of specific ligands to receptors on the cell’s surface; can take in various substances at once; more discriminating/specific than pinocytosis(cell-drinking) 12. Chromatids - one of two identical copies of DNA making up a chromosome(1 chromosome=2 sister chromatids) 13. Centromere - specialized region of the chromosome where two sister chromatids are most closely attached 14. Centrosome - structure present in the cytoplasm of animal cells, important during cell division; functions as a microtubule organizing

Transcript of AP Bio Unit 2 Review Shee1

Page 1: AP Bio Unit 2 Review Shee1

AP Bio Unit 2 Review Sheet

VOCAB1. Cytoskeleton - a network of microtubules, microfilaments, and intermediate filaments that branch throughout

the cytoplasm and serve a variety of mechanical, transport, and signaling functions; provides structural support to the cells for cell motility and regulation; mechanical support to cell, helps cell maintain its shape

2. Tight junctions - fusion of adjacent cell membrane, prevents leakage between cells3. Desmosome - anchoring junction w/ intermediate filaments cementing adjacent cells together4. Plasmodesma - (plasmodesmata) an open channel in the cell wall of a plant through which strands of cytosol

connect from an adjacent cell; allows cytoplasm of one cell to be continuous w/ cytoplasm of neighboring cell5. Hypotonic - a solution w/ a lower solute concentration compared to that inside a cell6. Hypertonic - a solution w/ a greater solute concentration than that inside a cell7. Isotonic - a solution w/ an equal solute concentration compared to that inside a cell8. Plasmolysis - phenomenon where a walled cell shrivels and the plasma membrane pulls away from the cell wall

as the cell loses water to a hypertonic environment9. Endocytosis - extracellular substances are incorporated into the cell in vesicles by an inward budding of the

plasma membrane; forms a food vacuole 10. Exocytosis - vesicles fuse with the plasma membrane and dump their contents to the outside of the cell; cellular

secretion of biological molecules 11. Receptor-mediated endocytosis - the process of importing specific macromolecules into the cell by the inward

budding of vesicles form from coated pits; occurs in the response to the binding of specific ligands to receptors on the cell’s surface; can take in various substances at once; more discriminating/specific than pinocytosis(cell-drinking)

12. Chromatids - one of two identical copies of DNA making up a chromosome(1 chromosome=2 sister chromatids)13. Centromere - specialized region of the chromosome where two sister chromatids are most closely attached14. Centrosome - structure present in the cytoplasm of animal cells, important during cell division; functions as a

microtubule organizing center, contains 2 centrioles; unit of centrioles and spindle fibers made of microtubules15. Centriole - a structure in the centrosome of an animal cell composed of cylinders of microtubule triplets; a pair

makes a centrosome16. Spindle fibers - made of microtubules, part of the cytoskeleton, separates chromosomes during cell division17. Kinetochore microtubules - a structure of proteins attached to the centromere that links each sister chromatid to

the spindle fibers; pull/ push chromosomes where they are needed during mitosis18. Nonkinetochore - elongates cell during mitosis19. Cleavage furrow - first sign of cytokinesis; a shallow groove in the cell surface near the old metaphase plate20. Cell plate - plant equivalent of cleavage furrow; a double membrane across the midline of a dividing plant cell,

eventually forms cell wall21. Restriction point - G1 checkpoint; at the end of the cell cycle's G1 phase, just before entry into S phase, making

the key decision of whether the cell should divide, delay division, or enter a resting stage. Many cells stop at this stage and enter a resting state called G0 stage

22. Thylakoid membrane - flattened membranous sac inside a chloroplast; function in the steps of photosynthesis that initially convert light energy to chemical energy

23. Stroma - viscous (dense) fluid outside of the thylakoids inside chloroplast; involved in the synthesis of organic molecules from carbon dioxide and water

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Study Questions1. Know the structure and function of all major organelles in both plant& animal cells.

Nucleus: contains a eukaryotic cell’s genetic library; general conspicuous membrane-bound cellular organelle contains most of the genes that control the entire cell, enclosed by a nuclear envelope which separates contents from cytoplasm. Nucleolus: most visible structure in nucleus; functions in the synthesis of ribosomesRibosome: a cytoplasmic organelle that is the site for protein synthesis complexes of RNA & protein, generally make proteins destined for membrane inclusionEndoplasmic reticulum: extensive network of tubules & sacs, continuous w/ outer membrane of nuclear envelopeSmooth ER: cytoplasmic surface lacks ribosomes, participates in synthesis f lipids, phospholipids, & steroids; carbohydrate metabolism, stores calcium ions necessary for muscle contraction; (in liver) contains an enzyme that catalyzes final step in conversion of glycogen to glucose; detoxifies drugs and poisonsRough ER: cytoplasmic side studded w/ ribosomes, manufacturers secretory proteins & membraneGolgi Apparatus: contains stacks of membrane bound structures called cisternae modifies, stores, & routes products of ER, Cis face receives products by accepting transport vesicles from the ER, Trans face transports molecules to other sites, contain enzymes to modify products from ER, sorts products for secretion, Trans face vesicles fuse w/ plasma membraneLysosome: membrane enclosed bag of hydrolytic enzymes, involved in breakdown of proteins, polysaccharides, lipids, nucleic acids, involved in intracellular digestion, phagocytosis, recycles cell’s own organic material; self-eating, reuses what it digestsVacuole: membrane enclosed sac, larger than a vesicleFood vacuole: formed by phagocytosis, stores food Contractile vacuole: found in freshwater protists; pumps excess water from the cellPeroxisome: consumes oxygen, contains enzymes that transfer hydrogen from various substrates to oxygen, produces hydrogen peroxide H2O2 has by product form intracellular compartments, bounded by a lipid bilayer membrane that separates their contents from the cytosol, contain membrane proteins for various functions, primarily removing the toxic peroxides from the cell and the metabolism of fatty acids

2. What determines the size of the cell? Range limited by metabolic requirements, surface area must be large enough to provide an adequate exchange surface for oxygen nutrients &wastes, needs to be larger enough to contain ribosomes, DNA, & enzymes3. What is the difference between prokaryotes & eukaryotes? Prokaryotes: found only in bacteria, no true nucleus, lacks nuclear envelope, genetic material in nucleoid region, no membrane bound organelles\ Eukaryotes: found in kingdom Protists, Fungi, Plantae, Animalia, true nucleus bound by nuclear envelope, nucleus contains genetic material, contains cytoplasm w/ cytosol (intracellular fluid) & membrane bound organelles4. Know the difference between diffusion, facilitated diffusion, & active transport. Diffusion: tendency for molecules of any substance to spread out into available space; net movement down concentration gradient; in absence of other forces i.e. pressure, substance diffuses from highlow concentration, , no energy required- Passive transport: diffusion of a substance across a biological membrane- Osmosis: passive transport of waterFacilitated Diffusion: diffusion of solutes across a membrane w/ help of transport proteins

>helps w/ diffusion of polar molecules/ions impeded by membrane’s phospholipid bilayer>protein binds solute, deposits solute on the other side

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Active Transport: always low to high, energy requiring, transport protein pumps a molecule across membrane against its concentration gradient, uses energy from ATP

Ex) Sodium-potassium pump: translocates 3 NA+ ions out of cell for every 2 K+ ions pumped into cell (keeps inside of cell negative)

5. Which molecules pass through a selectively permeable membrane easily? Most difficult? Easily: water, nonpolar molecules, those neutral in charger, simple smaller moleculesDifficult: ions (cations/anions) polar molecules, larger ex) carbs, larger sugars

6. Know the 5 phases of mitosis and what is occurring at the chromosome level. Interphase: nondividing stage, includes most of the cell’s growth and metabolic activities; about 90% of cell cycle

cell grows and copies its chromosomes in prep for cell division Prophase: chromatin condenses into a highly ordered structure called a chromosome in which the chromatin

becomes visible; attached to each other at a DNA element present on every chromosome called the centromere; centrosomes will be pushed apart to opposite ends of the cell nucleus by the action of molecular motors acting on the microtubules; nuclear envelope breaks down to allow the microtubules to reach the kinetochores on the chromosomes, marking the end of prophase

Prometaphase: chromatin attach to one another; centrosomes at opposite poles. Line up in perpendicular poles, line up at equator; nuclear envelope breaks into fragments and disappears; Microtubules emerging from the centrosomes at the poles (ends) of the spindle reach the chromosomes, now highly condensed

Metaphase: which condensed & highly coiled chromosomes align in the middle of the cell before being separated into each of the two daughter cells; centromeres of the chromosomes convene themselves on the metaphase plate (or equatorial plate), an imaginary line that is equidistant from the two centrosome poles

Anaphase: centromeres uncouple, sister chromatids move to opposite ends Telephase: Two daughter nuclei form in the cell. The nuclear envelopes of the daughter cells are formed from

the fragments of the nuclear envelope of the parent cell. As the nuclear envelope forms around each pair of chromatids as the nucleoli reappear; In animal cells a cleavage furrow develops where the metaphase plate used to be, pinching off the separated nuclei; in plant cell, cell plate appears, eventually forms cell wall

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7. Know the 3 phase of interphase. G1= gap 1 junction: cells make sure all organelles have copied themselves, have enough cytoplasm, and are growing; restriction point is at the end of G1 phase. This point is a series of safeguards to ensure the DNA is intact and that the cell is functioning normallySynthesis(S): when DNA makes exact copies of itself; single chromosome duplicate chromosomes (2 sister chromatids)G2= second growth phase; cell undergoes a period of rapid growth to prepare for mitosis; nucleus is well defined, bound by a nuclear envelope and contains at least one nucleolus; Although chromosomes have been replicated they cannot yet be distinguished individually because they are still in the form of loosely packed chromatin fibers8. Label parts of the cell membrane.

9. How does the amount of DNA change at different stages of cell division? G1: 46 chromosomes Synthesis: 92 chromosomes until cytokinesis

10. How does MPF form? How does the amount of MPF change during mitosis? MPF is formed when Cyclin combines with Cdk (cyclin-dependent kinases)

11. What is density-dependent inhibition? Phenomenon that causes cells to stop dividing after a single layer of cells is formed. (External physical factor on cell division)12. Know the structure of cilia/flagella *Outer microtubule doublet, plasma membrane, radial spoke, dynein arms, central microtubule

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13. Know the layers of a plant cell wall. *Middle lamella, Primary Wall, Secondary Wall

14. What occurs during glycolysis? (Where does it occur? How many ATP are required? Produced? How many NADH are produced?

During glycolysis, a glucose molecule (6-carbon sugar) is split into a 3-carbon sugar (glyceraldehyde phosphate). Glyceraldehyde phosphate is then rearranged into pyruvate. Glycolysis occurs in to CYTOPLASM and requires 2ATP (Energy Investment Phase). 2ATP, 2NADH, and 2 pyruvate molecules are produced (Energy Payoff Phase). 15. Glucose is split into what in glycolysis? Glyceraldehyde phosphate (G3P) -rearranged into pyruvate (pyruvic acid)16. What does pyruvic acid need to be converted into before entering the Mitochondria? Acetyl CoA17. What occurs during the Krebs’s Cycle? How many ATP are produced? How many NADH’S are produced? FADH 2?Pyruvate is converted into Acetyl CoA and enters the mitochondrion. 2 Carbons are oxidized and leave as CO2. Coenzymes are reduced to NADH AND FADH2.

1ATP, 3NADH, 2FADH2 but cycle repeats 2ATP, 6NADH, 4FADH2

18. What occurs during Electron Transport Chain? How many ATP’s are produced for each NADH? FADH 2? How many total ATP are produced in the ETC?

Energy is extracted from glucose molecules and is carried by NADH and FADH2. NADH and FADH2 pass their electrons down the ETC (cytochromes) to oxygen. (Exergonic process)

NADH= 2 net ATP, FADH2= 2ATP 19. What is chemiosmosis? How is ATP made through the use of a proton gradient? What is ATP synthase’s role in

this step?

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Chemiosmosis is the energy coupling mechanism that uses energy stored in the form of a hydrogen ion (proton) gradient across a membrane to drive the synthesis of ATP. (Creates most of ATP in cellular respiration)

ETC creates proton gradient by pumping H+ from mitochondrial matrix across inner membrane to the inter-membrane space

ATP synthase uses potential energy stored in proton gradient to make ATP by allowing H+ to diffuse down gradient, when protons diffuse through ATP synthase complex, the H+ (proton causes the phosphorylation of ADP to ATP

20. What is the difference between substrate level phosphorylation and oxidative phosphorylation? Substrate-level: requires 4ATP, not coupled, occurs during Glycolysis or Krebs’s Cycle, ADP + phosphate =

ATP Oxidative: produces 34ATP, requires oxygen as final electron acceptor, coupled reaction, occurs in ETC, ATP

directly synthesized from creation of protein (ATP synthase) gradient21. Where does Glycolysis occur? Krebs Cycle? ETC? *Glycolysis: cytoplasm/cytosol; *Krebs: mitochondria; *ETC: cristae (folding of mitochondria)--animal, thylakoid membrane of chlorophyll (plant)22. Which of the above processes occurs anaerobically?Glycolysis

23. What are the two types of fermentation? Alcoholic (produces ethanol), Lactic acid

24. What occurs during fermentation? Glycolysis occurs: oxidizes 2 glucose to 2 pyruvate (oxidizing agent = NAD+ not O2), 2ATP produced Recycles NAD+ from NADH, can produce ethanol or lactic acid

25. How many ATP are produced during fermentation? 2ATP

26. What are the two cycles in photosynthesis? Light Reaction, Calvin Cycle

27. What is required and produced in the light reactions of photosynthesis? Required: light (photons), splitting of water; Produced: 18 ATP and 12 NADPH

28. What is required and produced in the Calvin Cycle? Required: 18 ATP, 12 NADPH; Produced: 1 Glucose molecule

29. What is difference between C3, C4, and CAM plants? C3: open stomata during day, takes in CO2, releases O2; performs normal light and dark reactions, not exposed to extreme heatC4: 2 separate cells (mesophyll, bundle sheath cells) to offset photorespiration (when plants breakdown glucose into carbon dioxide instead of producing glucose), prevents water lossCAM: open stomata at night, closed during day, Calvin cycle occurs during the day, CAM plants found in desert

30. What is the difference between cyclic and noncyclic flow with respect of light reactions? Cyclic: simplest pathway, makes 6 additional ATP, excited electrons return to reaction center, does produce ATP without oxygen or NADPHNoncyclic: turns light energy into chemical energy, occurs in thylakoid membrane, produces ATP by noncyclic phosphorylation, produces NADPH and oxygen (byproduct), excited reaction does not return to reaction center

31. What is the difference between photosystem I and II in the light reactions of photosynthesis? I: specialized chlorophyll a P700 which absorbs best at 700nm, produces NADPHII: specialized chlorophyll a which absorbs best at 680nm, produces oxygen and electron (from splitting of water)

32. What is the most effective pigment for photosynthesis?

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Chlorophyll a33. What are other accessory pigments?

Chlorophyll b, carotenoids34. How many Total ATP and NADPH are required for photosynthesis to occur?

9ATP, 6NADPH

************************************ESSAY PROMPTS************************************

(1.) A. Solvent (chromatography solution) moves up the chromatography paper by capillary action which occurs as a result of the attraction of solvent molecules to the paper and the attraction of solvent molecules to one another-As solvent moves up paper, it carries along any substances dissolved in it-Pigments move up paper at different rates because they are not equally soluble in solvent & are attracted at different degrees to chromatography paper’s fibers through formation of hydrogen bonds-Beta carotene very soluble, Xanthophyll less soluble (contains oxygen); Chlorophylls contain oxygen and nitrogen (least soluble in solvent)B. Chlorophyll a: primary photosynthetic pigment in plants, located at the reaction center of photosystems, specialized chlorophyll a can participate in light reactions (green)-Chlorophyll b: accessory pigment (yellow-green), Carotenoids (carotene, xanthophyll): accessory pigments absorb a wider range of wavelengths, transfer light energy to chlorophyll a at reaction center carotenoids protect photosynthetic system from UV raysC. Rf= distance solvent migrated (mm)

Distance solvent front migrated (mm)(2.) A. Membranes are selectively permeable: allows some substances to cross more easily than others

a. Membranes held together by hydrophobic interactions (weak)b. Phospholipids = most abundant lipids in membranes, antipathic (hydrophilic , hydrophobic regions)c. Consists of glycoproteins (cell-cell recognition), carbohydrates (cell-cell recognition), cholesterol

(controls fluidity) , peripheral proteins, integral proteins, glycolipids (cell-cell recognition), transport proteins (bind to substance and move it across membrane or may provide tunnel for passage of substances)

B. Membranes in ATP synthesis (cellular respiration) -Cellular Respiration: the inner membrane of the mitochondria allows a concentration gradient to be made, with more H+ ions outside that membrane but still inside the outer membrane forming a proton pump. The H+ ions then move down their concentration gradient by going through ATP synthase, driving the synthesis of ATP from ADP + Pi (chemiosmosis)

(3.)B. Control: Cuvette #1

- Cuvette #1 contains unboiled chloroplasts exposed to light (simulates a typical scenario), therefore contents in cuvette photosynthesize at a normal rate generates more electrons as exposed to more light and as water molecules are split

C. Electrons are generated by the splitting of water in photosynthesis

-Cuvette 2: Manipulated variable, No light = no photosynthesis (covered in a foil capsule), photosynthesis requires light, few electrons produced as a result

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-Cuvette 3: Manipulated variable, boiled chloroplast: ETC doesn’t work because proteins of ETC are denatured when chloroplasts are boiled no photosynthesis represented by little change in production of electrons