Biology 6-8 – Flashcards
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The outputs of photosynthesis
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glucose and oxygen
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main function of a photosynthetic pigment molecule is
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absorb light energy
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stages of the Calvin cycle
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fixation of carbon dioxide, reduction of carbon dioxide, regeneration of RuBP
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two major chemical units for photosynthesis are
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carbon dioxide and water
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solar energy is converted into the chemical energy of a carbohydrate molecule during
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the process of photosynthesis
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structure that carries out photosynthesis in plant cells
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chloroplast
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fluid filled interior of a chloroplast is
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stroma
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the Calvin cycle reactions occur in the
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stroma of the chloroplast
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Photosystems I & II consist of?
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electron acceptor, chlorophyll molecules, carotenoid molecules
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the color that a pigment molecule appears is the portion of visible light that it
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reflects
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flattened sacs within the storm that are sometimes arranged in stacks called grana
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thylakoids
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in a C4 plant, the Calvin cycle occurs only in the
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mesophyll cells
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reduction is the process by which a molecule
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gains a hydrogen atom
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reaction involving oxidation and reduction at the same time is referred to as
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redox reaction
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when a molecule loses an electron during a chemical reaction its called
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oxidation
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a molecule of RuBP is attached to a molecule of carbon dioxide during?
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carbon dioxide fixation
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the passage of electrons along a series of membrane-bound carrier molecules from a higher to lower energy level is called
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electron transport chain
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when the chlorophyll at the reaction center of photosystem II loses its electrons, these are replace by electrons from:
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splitting water
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produced in the light reaction of photosynthesis is
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ATP and NADPH
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in C4 plants, chloroplasts are located in
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bundle sheath cells and mesophyll cells
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the electron lost from the photosystem I is replaced by an electron from
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photosystem II
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coenzymes
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non-protein helpers that assist enzymes that carry out oxidation during cellular respiration
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glycolysis
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occurs in the cytoplasm outside the mitochondria, is the breakdown of glucose to two molecules of pyruvate. two ATP are gained
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citric acid cycle
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takes place in the matrix of mitochondria. able to produce 2 ATP per glucose molecules.
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electron transport chain
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a series of electron carriers in the cristae of mitochondria. energy is released and captured as the electrons move from a higher energy to a lower energy state. This energy will be used for the production of ATP.
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fermentation
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anaerobic breakdown of glucose, resulting in the production of two ATP per glucose, ensures that ATP is available for cellular processes.
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inputs of cellular respiration
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oxygen and glucose
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the preparatory steps, citric acid cycle and the electron transport chain occur inside
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mitochondria
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lactic acid fermentation order
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2 ATP are invested, NADH is produced, lactic acid is produced, NADH gives up electrons and hydrogen to another molecule, pyruvate is produced, 4 ATP are produced for a net gain of 2 ATP.
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which is produced during the citric acid cycle
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NADH and FADH2
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glycolysis
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4 ATP (2 as a net gain)
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citric acid cycle
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2 ATP
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Electron transport chain
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34 ATP
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where does the citric acid cycle occur?
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matrix of the mitochondria
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what are the reactants for cellular respiration?
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oxygen and glucose
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fermentation produces?
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lactate
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the phase of cellular respiration that takes place outside the mitochondrion, does not require the presence of oxygen, and produces two ATP molecules called?
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glycolysis
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for each molecule of glucose, glycolysis produces
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the same number of ATP as the citric acid cycle
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the enzyme ATP synthase is located on the cristae of the mitochondrion's
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inner membrane
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in the electron transport chain cellular respiration, electrons are passed from one molecule to the next. As the electrons move down the chain their energy levels change from
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high energy level to lower energy level.
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fats and oils are processed before they enter cellular respiration and are broken down into
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glycerol and fatty acids
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the outputs from the citric acid cycle are
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NADH, CO2, ATP, FADH2
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what occurs during the energy-investment step of glycolysis?
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ATP is broken down to ADP
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in an animal and human cell, the end result of fermentation is
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lactic acid
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oxidation removes what from a molecule?
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hydrogen ions
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the inter membrane space is found between?
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the outer and inner membranes of the mitochondrion
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the amount of oxygen needed to metabolize lactate is?
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oxygen deficit
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steps of glycolysis
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energy-harvesting step and energy-investment step
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during periods of cell division, DNA and its associated proteins are wrapped and packaged into a short, warlike structure called
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chromosome
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repeating sequence of events in eukaryotes that involves cell growth and cell division and includes the stages G1, S, G2, and mitosis is called
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cell cycle
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two types of molecules that make up chromatin are
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proteins and DNA
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when proto-oncogenes mutate, they become cancer-causing genes called
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oncogenes
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genes that code for proteins that promote the cell cycle and inhibit apoptosis are
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proto-oncogenes
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which phase ends in the formation of 2 daughter cells?
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mitosis
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characteristics that are common to cancer cells
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form tumors, do not undergo apoptosis, lack of differentiation, abnormal nuclei
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the process of asexual reproduction known as binary fission occurs in what group of organisms?
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bacteria
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the mitotic phase during which daughter chromosomes are present at opposite poles and nuclear envelopes reform is?
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Telophase
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the process by which a cancer travels through the blood and lymphatic vessels and then invades new tissues is?
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metastasis
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the attachment point of two chromatids
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centromere
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external signals received at a cell's plasma membrane that promote cell division
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growth factors
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the components of a nucleosome are
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histones and DNA
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what happens during the G2 checkpoint?
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verification that DNA has replicated
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DNA replication occurs during the part of interphase called
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S phase
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in animal cells, cytokinesis starts with the formation of a
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cleavage furrow
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what happens during cell growth or interphase?
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replication of DNA and duplication
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the mitotic phase during which the nuclear envelope disappears, the chromosomes begin to condense, become visible, and appear scattered in the cytoplasm
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prophase
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a mass of cells that have lost all restraint in division and are piled on top of one another is
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a tumor
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collection of fibers that pulls sister chromatids apart during mitosis
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spindle
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the divider across a plant cell that marks the location for a new cell walls and plasma membranes
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cell plate
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angiogenesis
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formation of new blood vessels promoted by secretions from cancer cells
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the process whereby a portion of DNA breaks off one chromosome and reattaches to another chromosome is
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translocation
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during G2 phase what occurs?
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proteins required for microtubules are acquired and synthesized
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the phenomenon that prevents cells from dividing and overflowing is called?
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contact inhibition
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what is located at the tips of chromosomes and shorten with each cell division?
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telomeres
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internal signals that trigger cell growth
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cyclins and kinases
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carcinogenesis
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development of cancer
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telomeres can be rebuilt via the action of the enzyme
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telomerase
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external signals received at a cell's plasma membrane that promote cell division
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growth factors
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area of a cell midway between the poles, where spindle fibers overlap is called
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spindle equator
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primary microtubule organizing center in a cell
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centrosome
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RB gene is a
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tumor suppressor gene
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Identify the cellular structures where photosynthesis occurs and list their functions
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chloroplasts - organelles that carry on photosynthesis stroma - a fluid filled area that the membrane surrounds; involved in the synthesis of carbohydrates during photosynthesis. thylakoids - flattened sac within a granum whose membrane contains chlorophyll and where the light reactions of photosynthesis occur grana - stack of chlorophyll-containing thylakoids in a chloroplast. chlorophyll - green pigment that absorbs solar energy.
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Recognize what is meant by the terms reduction and oxidation.
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Reduction - when a molecule gains electrons and hydrogen ions. Oxidation - when a molecule gives up electrons and hydrogen ions.
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Describe the function of photosynthetic pigments.
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absorb energy from the sun
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Explain the flow of electrons in the light reactions.
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the light reactions capture the sun's energy and store it in the form of a hydrogen ion gradient; used to produce ATP molecules and NADPH. both photosystems receive protons. Energy is passed from one pigment into a pair of chlorophyll molecules, called reaction center. PS II - splits water; sends energized electrons, received from the reaction center down an electron transport chain. electron transport chain - establishes an energy; a series of carriers pass electrons from to the other releasing energy stored in the form of a hydrogen ion; later ATP is produced. PS I - produces NADPH; when the PS I pigment complex absorbs solar energy electrons leave it reaction and are captured. NADP+ becomes NADPH.
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Explain how ATP and NADPH are generated in the light reactions of photosynthesis.
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ATP Production - water is split, H+ remain in the thylakoid space; electrons move from the carrier down the electron transport chain; electrons give up energy; more H+ in the thylakoid space; H+ flow down the gradient, and energy is released; this causes the enzyme ATP synthase to change its shape and produce ATP. NADPH Production - NADP+ is a coenzyme that accepts electrons, becoming NADPH. NADP+ receives electrons at the electron pathway in the thylakoid membrane and then picks up a hydrogen ion to become NADPH.
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Summarize the three stages of the Calvin cycle and describe the major event that occurs during each stage.
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Fixation of carbon dioxide - CO2 from the atmosphere is attached to RuBP and the result is is two 3 carbon molecules. Reduction of Carbon dioxide - NADPH and ATP supply needed electrons. Electrons are added from NADPH and carbon dioxide is reduced to form G3P - a carb. Regeneration of RuBP - 5 molecules of G3P are used to re-form 3 molecules of RuBP, (which are needed to begin the next cycle) some of the ATP production by the light reactions is used.
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Describe both the advantages and disadvantages of C4 photosynthesis over C3 photosynthesis.
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when weather is moderate C3 plants have the advantage, but when the weather becomes hot and dry C4 plants have their chance to take over.
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Compare and contrast the leaf structure of a C3 plant with that of a C4 plant.
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C3 plant - mesophyll cells are arranged in rows and contain chloroplasts. C4 plant - mesophyll cells are arranged in rings around bundle sheath cells. both have chloroplasts.
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Explain CAM photosynthesis and describe the conditions under which plants can use it.
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desert environments at night; CAM plants use C3 molecules to fix CO2 forming C4 molecules; next day CO2 is released and enters the Calvin Cycle within the same cells. Carbon fixation - at night Calvin cycle - during the day
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cellular respiration
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metabolic reaction that uses the energy from carbohydrates, fatty acid, or amino acid breakdown to produce ATP molecules.
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Explain the role of glycolysis in a cell.
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takes place outside the mitochondria, within the cytoplasm of the cell; glucose is broken down to two molecules of pyruvate. Glycolysis is divided into the energy-investment step, when some ATP is used to begin the reactions and the energy-harvesting steps.
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Give examples of products made by fermenting yeast and bacteria.
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alcohol and bread
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Recognize how alternate metabolic pathways allow proteins and fats to be used for ATP production.
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glycerol and fatty acids from fats and amino acids from proteins can undergo cellular respiration by entering glycolysis and/or the citric acid. also provide substrates for the synthesis of fats and proteins.
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Summarize the purpose of cellular reproduction
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it replaces worn ourn-out or damaged tissue new red blood cells, skin cells, cells that line your respiratory and digestive tract. helps repair injuries, helps reproduction of certain organisms necessary for the production of both new cells and new organisms.
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Summarize the events in each phase of mitosis.
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the duplicated nuclear contents of the parent cell are distributed equally to the daughter cells. the daughter nuclei are identical to the parent cell and to each other - they all have to same number and kinds of chromosomes. the sister chromatids separate and are now called daughter chromosomes. Interphase - eukaryotic cell duplicates the contents of the cytoplasm and DNA replicates in the nucleus. Prophase - the chromosomes are condensing, spindle begins to assemble between the separating chromosomes, nucleolus disappears, spindle fibers attach to the chromosomes. Metaphase - the chromosomes are aligned at the spindle equator midway between the spindle poles. Anaphase - sister chromatids separate and become daughter chromosomes. Telophase/Cytokinesis - the spindle disappears as new nuclear envelopes form around the daughter chromosomes.
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Describe the process of apoptosis
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programmed cell death. Allows an organism to control cell death. the cell rounds up and loses contact with its neighbors.
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Explain the role of telomerase in stem cells and cancer cells.
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telomerase can rebuild telomeres. the gene codes for telomerase is turned on in cancer cells. The telomeres do not shorten and cells divide over and over again.
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Identify the relationship between certain genes and cancer.
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BRCA1 - breast cancer RB gene - eye tumor - retinoblastoma. RET gene - thyroid cancer
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Describe the characteristics of cancer cells.
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lack differentiation - lose specialization, abnormal nuclei - nuclei is enlarged and contain abnormal number of chromosomes. do not undergo apoptosis - cells do not respond normally to signals form tumors - lose all restraint; pile on top of each other and grow multiple layers undergo metastasis and promote angiogenesis - cells from a malignant tumor may travel through the blood or lymph to start new tumors elsewhere in the body. Angiogenesis - formation of new blood vessels.
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Describe the factors that reduce the risk of cancer.
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avoid smoking, sunbathing, and excessive alcohol consumption. weight loss follow dietary guidelines
