4 Cellular Metabolism Flashcards
<p>aer-</p>
<p>air</p>
<p>(aerobic respiration)</p>
<p>an-</p>
<p>without</p>
<p>(anaerobic respiration)</p>
<p>ana-</p>
<p>up<br></br>
| (anabolism)</p>
<p>cata-</p>
<p>down<br></br>
| (catabolism)</p>
<p>co-</p>
<p>with</p>
<p>(coenzyme)</p>
<p>de-</p>
<p>undoing</p>
<p>(deanimation)</p>
<p>mut-</p>
<p>change</p>
<p>(mutation)</p>
<p>-strat</p>
<p>spread out<br></br>
| (substrate)</p>
<p>sub-</p>
<p>under</p>
<p>(substrate)</p>
<p>-zym</p>
<p>causing something to ferment</p>
<p>(enzyme)</p>
<p>enzyme</p>
<p>protein that catalyzes a specific biochemical reaction</p>
<p>cellular metabolism</p>
<p>the sum total of chemical reactions in the cell</p>
<p>What are the two types of metabolic reactions and pathways?</p>
<p>anabolic</p>
<p>catabolic</p>
<p>anabolism</p>
<p>(anabolic metabolism)</p>
<p>synthesis of larger molecules from smaller ones</p>
<p>catabolism</p>
<p>(catabolic metabolism)</p>
<p>breakdown of larger molecules</p>
<p>dehydration synthesis</p>
<ul>
<li>anabolic process that joins small molecules by enzymaticallyreleasing the equivalent of H₂O</li>
<li>forms carbohydrates, fats, proteins, and nucleic acids</li>
</ul>
<p></p>
<p>monosaccharide + monosaccharide⇄disaccharide + water</p>
<p>amino acid + amino acid⇄ dipeptide molecule + water</p>
<p>Are metabolic reactions reversible?</p>
<p>often, but different enzymes often catalyze corresponding anabolicand catabolic reactions</p>
<p>How do enzymes speed metabolic reactions?</p>
<p>lower the amount of activation energy required by straining chemical bonds in substrate</p>
<p></p>
<p>substrate + enzyme⟶ enzyme-substrate complex⟶ product + enzyme</p>
<p>substrate</p>
<p>molecule on which an enzyme acts</p>
<p>What is catalase, where is it found, and what is its substrate? Give an example.</p>
<ul>
<li>an enzyme</li>
<li>in the peroxisomes of liver and kidney cells</li>
<li>hydrogen peroxide, a toxic by-product of certain metabolic reactions</li>
<li>EXAMPLE: When hydrogen peroxide is poured on a wound, cells release catalase, and the hydrogen peroxide is broken down, releasing oxygen; the foam removes debris.</li>
</ul>
<p>active site</p>
<p>part of an enzyme that temporarily binds a substrate</p>
<p>What factors affectthe rate of enzyme-catalyzed reactions?</p>
<ul>
<li>concentration ofenzyme <u>or</u> substrate molecules in the cell; higher concentration = faster</li>
<li>efficiency of the enzyme; some can catalyze only a few reactions per second, some can handle hundreds of thousands</li>
</ul>
<p>metabolic pathway</p>
<p>series of linked, enzyme-controlled chemical reactions</p>
<p>lipase</p>
<p>enzyme that breaks down fat (lipid)</p>
<p>protease</p>
<p>enzyme that breaks down protein</p>
<p>amylase</p>
<p>enzyme that hydrolyzes polysaccharides (starch, amylum)</p>
<p>amylum</p>
<p>starch, polysaccharide</p>
<p>What digestive enzyme catalyzes the breakdown of the sugar sucrose?</p>
<p>sucrase</p>
<p>What is sucrose, and what is it made of?</p>
<ul> <li>disaccharide</li> <li>table sugar</li> <li>glucose and fructose</li> </ul>
<p>maltase</p>
<p>enzyme that splits maltose</p>
<p>What is maltose, and what is it made of?</p>
<ul>
<li>disaccharide produced by the breakdown of starch</li>
<li>two glucose molecules</li>
</ul>
<p>lactase</p>
<p>enzyme that splits lactose</p>
<p>What is lactose, and what is it made of?</p>
<ul>
<li>disaccharide in milk</li>
<li>made of glucose and galactose</li>
</ul>
<p>hydrolysis</p>
<ul>
<li>catabolicprocess that breaks up large molecules by enzymatically adding a water moleculeH₂O</li>
<li>breaks down carbohydrates, fats, proteins, and nucleic acids</li>
</ul>
<p></p>
<p>disaccharide + water⇄monosaccharide + monosaccharide</p>
<p>dipeptide molecule + water⇄amino acid + amino acid</p>
<p>What is ATP, what is it made of, and what does it do?</p>
<ul>
<li>adenosine triphosphate</li>
<li>a molecule made of an adenine, a ribose, and three phosphates</li>
<li>it carries energy in its chemical bonds that is released for use when they are broken</li>
</ul>
<p>What two ways do rate-limiting enzymes affect the rate of a metabolic pathway?</p>
<ol>
<li>they become ineffectual in high concentrations of substrate</li>
<li>they are inhibited by the pathway's product (negative feedback)</li>
</ol>
<p>What is ADP, where does it come from, and what happens to it?</p>
<ul>
<li>adenosine triphosphate</li>
<li>when the bonds of ATP's third phosphate group are broken for energy, it becomes ADP</li>
<li>it is resynthesized into ATP via cellular respiration</li>
</ul>
<p>What is a cofactor, and what does it do?</p>
<ul>
<li>a non-protein component</li>
<li>activates an enzyme by giving the active site an appropriate shape or helping bind enzyme and substrate</li>
</ul>
<p>What is a coenzyme, how does it function, and what are some examples?</p>
<ul> <li>small organic molecule</li> <li>acts as a cofactor</li> <li>many are vitamins</li> </ul>
<p>vitamins</p>
<p>essential organic molecules that must come from diet because human cells can't synthesize enough or any</p>
<p>What are enzymes made of?</p>
<p>almost all are proteins, but a few are RNA</p>
<p>What is energy? Give some examples.</p>
<ul>
<li>the ability to do work</li>
<li>heat, light, sound, electricity, mechanical energy, and chemical energy</li>
</ul>
<p>cellular respiration</p>
<p>a biochemical pathway that releases energy from organic compounds and makes it available for cellular use</p>
<p>What are the three series of reactions in cellular respiration?</p>
<ol> <li>glycolysis</li> <li>the citric acid cycle</li> <li>electron transport chain (oxidative phosphorylation)</li> </ol>
<p>aerobic</p>
<p>in the presence of oxygen</p>
<p>anaerobic</p>
<p>without the presence of oxygen</p>
<p>Of the two types of reactions in cellular respiration, which forms more ATP molecules?</p>
<p>aerobic</p>
<p>How much energy is captured and how much is lost in cellular respiration?</p>
<p>almost half is captured as ATP; the rest is released as body heat</p>
<p>What are the three main events in glycolysis?</p>
<ol>
<li>phosphorylation (two phosphate groups added) and ATP primes the glucose</li>
<li>glucose molecule is split in two</li>
<li>NADH is produced, more ATP is synthesized, and two pyruvic acid molecules result</li>
</ol>
<p>How many ATP molecules are gained per glucose moleculethrough glycolysis?</p>
<p>2 are used, and 4 are produced, making the net gain 2</p>
<p>glycolysis</p>
<p>the breaking of glucose</p>
<p>What does NADH do in cellular respiration? What happens without sufficient oxygen?</p>
<ul>
<li>electron carrier produced in glycolysis and recycled in the electron transport chain</li>
<li>without oxygen, NADH reacts with pyruvic acid</li>
</ul>
<p>How is lactic acid formed? How does it affect cellular respiration?</p>
<ul>
<li>When the electron carrier NADH reacts with pyruvic acid in the absence ofsufficient oxygen receptors</li>
<li>inhibits glycolysis, diffuses into the blood and is recycled in the liver when oxygen levels return to normal</li>
</ul>
<p>What two substances are required for the citric acid cycle to begin?</p>
<p>pyruvic acid and oxygen</p>
<p>How does the citric acid cycle begin?</p>
<p>acetyl CoA combines with oxaloacetic acid to form citric acid and CoA</p>
<p>Name three important consequences of the citric acid cycle.</p>
<p>for each citric acid molecule ...</p>
<ol>
<li>one ATP is produced</li>
<li>eight hydrogen atoms with high-energy electrons are transferred to NAD⁺ and related FAD:<br></br>
NAD⁺ + 2H⟶ NADH + H⁺<br></br>
FAD + 2H⟶ FADH₂</li>
<li>as citric acid reacts to form oxaloacetic acid, two CO₂ molecules are produced</li>
</ol>
<p>What happens to the CO₂ produced in the citric acid cycle?</p>
<p>it dissolves into the cytoplasm, diffuses from the cell, enters the bloodstream, and is excreted by the respiratory system</p>
<p>What two compounds carry most of the energy from the glucose molecule to the electron transfer chain?</p>
<p>NADH and FADH₂</p>
<p>electron transport chain</p>
<p>a series of oxidation-reduction reactions that takes high-energy electrons from glycolysis and the citric acid cycle to form water and ATP</p>
<p>Where do the electron transport chain's enzyme complexes lie?</p>
<p>the folds of the inner mitochondrial membranes (cristae)</p>
<p>If stretched out, how long is the inner mitochondrial membrane?</p>
<p>could be 45 times as long as the cell membrane</p>
<p>What happens to an electron's energy as it moves along the transport chain?</p>
<p>it is gradually transferred to ATP synthase</p>
<p>What is ATP synthase, and what role does it play in the electron transport chain? What kind of reactions are these?</p>
<ul> <li>enzyme complex</li> <li>uses energy from passing electrons to phosphorylate ADP</li> <li>oxidation-reduction</li> </ul>
<p>The final enzyme in the electron transport chain gives up a pair of electrons that do what?</p>
<p>combine with hydrogen ions (from NADH and FADH₂) and an atom of oxygen to form a water molecule<br></br>
2e⁻ + 2H⁺ + ½O₂⟶ H₂O</p>
<p>How many net ATP molecules are produced per glucose molecule by glycolysis, the citric acid cycle, and the electron transport chain?</p>
<p>glycolysis: 2</p>
<p>citric acid cycle: 2</p>
<p>electron transport chain: 32-34</p>
<p>What is genetic code and what process is it used in?</p>
<ul>
<li>the correspondence between DNA triplets and mRNA codons and the amino acids they specify</li>
<li>used in protein synthesis</li>
</ul>
<p>chromosomes</p>
<p>threadlike structure built of DNA wrapped around proteins (histones)</p>
<p>gene</p>
<p>part of a DNA molecule that encodes information for making a particular protein</p>
<p>genome</p>
<p>complete set of genetic instructions for an organism</p>
<p>genomics</p>
<p>study of all the genetic information in an individual organism</p>
<p>Name DNA's four nitogenous bases and their two possible combinations.</p>
<p>adenine, thymine, cytosine, and guanine</p>
<p>AT and GC</p>
<p>complementary base pairs</p>
<p>pairs of nitrogenous bases in DNA</p>
<p>purines</p>
<p>adenine and guanine</p>
<p>pyrimidines</p>
<p>thymine and cytosine</p>
<p>DNA polymerase</p>
<p>enzyme that catalyzes the pairing of nucleotides to form DNA</p>
<p>When does DNA replication happen?</p>
<p>during the S phase of interphase</p>
<p>Name the four nitrogenous bases of RNA.</p>
<p>adenine, thymine, uracil, and guanine</p>
<p>What base does RNA have in place of DNA's thymine, and what does it pair with?</p>
<ul>
<li>uracil</li>
<li>adenine</li>
</ul>
<p>transcription</p>
<p>the process of copying DNA information into an RNA sequence</p>
<p>What are the three types of RNA?</p>
<p>messenger RNA, transfer RNA, and ribosomal RNA</p>
<p>mRNA</p>
<ul> <li>messenger RNA</li> <li>synthesized in nucleus</li> <li>carries instructions for synthesizing protein into cytoplasm</li> </ul>
<p>RNA polymerase</p>
<p>enzyme that binds with DNA, exposes sections of it for RNA nucleotides to pair with, then releases mRNA</p>
<p>codons</p>
