Lecture 22 Flashcards
<p>Metabolism is highly connected vis these \_\_\_\_\_\_\_\_\_\_ ? </p>
<p>central metabolic "highways" (glycolysis, Krebs, etc). in plants, animals and bacteria. </p>
<p>Most microbes oxidize \_\_\_\_\_\_\_\_\_ as their primary source of cellular respiration. What is this called? </p>
<p>carbohydrates
carbohydrate catabolism</p>
<p>\_\_\_\_\_\_ is the most common carbohydrate energy source used by cells. </p>
<p>glucose</p>
<p>To get energy from glucose, microbes use these two general processes? </p>
<p>cellular respiration and fermentation</p>
<p>First step of cellular respiration and fermentation? </p>
<p>glycolysis </p>
<p>Three principal steps of cellular respiration?
Embden-Meyerhof pathway is what? </p>
<p>1. Glycolysis (Embden-Meyerhof pathway)
2. Krebs cycle
3. ETC</p>
<p>Steps in fermentation? </p>
<p>1. Glycolysis
| 2. Fermentative pathways </p>
<p>Glucose (a 6 carbon sugar) is broken down into two 3-carbon sugars
what happens during this process? and what is formed?</p>
<p>glycolysis
These sugars are oxidized (losing electrons), releasing energy and their atoms are rearranged to form two molecules of pyruvic acid. </p>
<p>Glycolysis does not require what? </p>
<p>oxygen; it can occur whether oxygen is present or not </p>
<p>The generation of ATP in glycolysis is due to what? </p>
<p>substrate-level phosphorylation (SLP)</p>
<p>The oxidation of glucose to pyruvic acid produces what? </p>
<p>ATP and NADH</p>
<p>What is ATP made up of?
ATP is generated during certain \_\_\_\_\_\_\_\_\_ rxns, consumed in \_\_\_\_\_\_\_ rxns. </p>
<p>nucleoside adenosine to which 3 phosphate molecules are bonded in series. It is the prime energy currency in all cells
-exergonic rxns, endergonic rxns</p>
<p>Oxidation reduction (redox) rxns in microbes typically involves rxn between one or more intermediates called \_\_\_\_\_\_\_ ? </p>
<p>Carriers</p>
<p>Electron carries can be divided into 2 classes:</p>
<p>those that are freely diffusible (coenzymes) and those that are firmly attached to enzymes in the cytoplasmic membrane (prosthetic groups)</p>
<p>The fixed carriers function in membrane associated e- transport rxns that we'll see in \_\_\_\_\_\_ ?</p>
<p>the ETC</p>
<p>Common diffusiblecarriers include the ?</p>
<p>coenzymes Nicotinamide adenine dinucleotide (NAD+) and NAD- Phosphate (NADP+)</p>
<p>NAD+ and NADP+ are e- + \_\_\_\_\_\_ carriers, transporting \_\_\_\_\_\_\_ ?</p>
<p>proton carriers, transporting 2e-s and 2H+ at a time. </p>
<p>The electrons from the oxidation of glucose are temporarily stored by \_\_\_\_\_\_ ? Which is also generated during the Krebs cycle </p>
<p>NADH </p>
<p>If NAD+ gets reduced it is picking up \_\_\_\_\_\_\_\_ and producing \_\_\_\_\_\_\_ . </p>
<p>two hydrogen atoms, and producing NADH + H+</p>
<p>NADH is a good \_\_\_\_\_\_\_ and NAD+ a good \_\_\_\_\_\_ . </p>
<p>electron donor, electron acceptor </p>
<p>Glycolysis begins with a \_\_\_\_\_\_\_\_\_\_ or \_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ stage. And what happens? </p>
<p>preparatory stage, or energy investment stage
-glucose enters the cell and is phosphorylated </p>
<p>Preparatory Stage of Glycolysis: order of events? </p>
<p>1 . requiring the expenditure of 1 ATP to produce Glucose-6-phosphate.
2. This molecule is isomerized (rearranged) to fructose-6-phosphate
3. a second phosphorylation leads to the production of fructose 1,6-diphosphate
4. the enzyme aldolase splits this molecule to form 3-carbon molecules: glyceraldehyde 3-phosphate (GP) and its isomer, dihydroxyacetone phosphate (DHAP), which is readily converted to GP as GP is consumed in the next step. </p>
<p>During the preparatory stage of glycolysis, all rxns proceed without what? </p>
<p>redox (oxidation-reduction) changes</p>
<p>Preparatory stage of glycolysis
\_\_\_\_\_\_ are used
Glucose is split to form \_\_\_\_\_\_\_\_\_</p>
<p>- 2 ATP are used (Phosphorylation)
-2 glucose-3-phosphate</p>
<p>Energy - Conserving Stage of Glycolysis -- steps? </p>
<p>Comes right after preparatory stage
1. enzyme converts each GP to 1,3 diphosphoglyceric acid (2 of these molecules form given two GP's from preparatory stage)
2. High energy P is moved to ADP, forming ATP, the first ATP production of glycolysis via SLP.
3. An enzyme relocates the remaining phosphate of the 3-phosphoglyceric acid to make 2-phosphoglyceric acid in preparation for the next step
4. by the loss of a water molecule, 2 phosphoglyceric acid is converted to phosphoenolypyruvic acid or PEP. In the process the phosphate bond is upgraded to a high energy bond.
5. This high energy bond is transferred from PEP to ADP to form ATP. So for each individual glucose molecule, 2 ATP and 2 molecules of 3-C compound called pyruvic acid would be formed during this step)</p>
<p>How is GP oxidized during the first step of energy-conserving stage of glycolysis? The enzyme (GP dehydrogenasease) couples this reaction with? </p>
<p>GP is oxidized by the transfer of two hydrogen atoms to NAD+ to form NADH.
-couples with the creation of a high energy bond between the sugar and a phosphate </p>
<p>SLP - results in what?
</p>
<p>Substrate level phosphorylation. Type of metabolic rxn that results in the formation of ATP
SLP is the generation of ATP where you directly transfer P to ADP from a reactive intermediate (PEP in this case) generated during enzymatic conversion of one organic compound to another</p>
<p>In the energy conserving stage of glycolysis, the two 3-carbon molecules (GP) are oxidized in several steps to two molecules of pyruvic acid. HOW? </p>
<p>In these rxns, two NAD+ are reduced to NADH in the first step of conserving.
Four molecules of ATP are made by SLP: 2 from step 2 and 2 from step 5 (where high energy phosphate bonds are)
**remember everything is double since this happens twice for every glucose molecule </p>
<p>Net ATP gain from glycolysis total from both GP molecules </p>
<p>2 </p>
<p>Single GP molecule yields production of </p>
<p>One glucose molecule produces four ATP, two NADH, and two pyruvate molecules during glycolysis. ????</p>
<p>The acetyl group is attached to coenzyme A via a what? </p>
<p>high energy bond</p>
<p>Acetyl-CoA is a very common what? </p>
<p>intermediate, ex. oxidation of fats and amino acids </p>
<p>Bride/transition step produces what? </p>
<p>2 molecules CO2
2 molecules NADH
2 molecules of Acetyl-CoA</p>
<p>As Acetyl-CoA enters the Krebs cycle, the CoA does what?
| </p>
<p>detaches from the acetyl group</p>
<p>In cellular respiration, pyruvate is completely oxidized to \_\_\_\_\_\_ in the Kreb's cycle. </p>
<p>CO2</p>
<p>In fermentation, the pyruvate is reduced and converted into \_\_\_\_\_\_\_\_ products that are subsequently \_\_\_\_\_\_\_\_\_ . </p>
<p>fermentation products, subsequently excreted </p>
<p>First molecule of preparatory stage of glycolysis that uses ATP to form second molecule</p>
<p>glucose (6 carbons)</p>
<p>second molecule of preparatory stage of glycolysis</p>
<p>glucose-6-phosphate (ATP used to create this molecule)</p>
<p>in the third step of the preparatory stage of glycolysis, glucose-6-phosphate is \_\_\_\_\_\_\_ and becomes \_\_\_\_\_\_\_</p>
<p>isomerized, and becomes fructose-6-phosphate</p>
<p>in the fourth step of the preparatory stage of glycolysis, fructose-6-phosphate becomes phosphorylated again using \_\_\_\_\_\_\_ to produce \_\_\_\_\_\_\_\_\_</p>
<p>using ATP to produce fructose 1,6 - diphosphate </p>
<p>in the fifth step of the preparatory stage what splits fructose 1,6 - diphosphate? And what does this form? </p>
<p>the enzyme aldolase,
glyceraldehyde 3-phosphate (GP), and its isomer, dihydroxyacetone phosphate (DHAP), which is readily converted to GP.
GP is consumed in the next step.</p>
<p>During this stage all the reactions, including the consumption of 2 ATP proceed without any redox oxidation-reduction reactions</p>
<p>preparatory stage of glycolysis</p>
<p>Steps 6-10 in glycolysis are referred to as? </p>
<p>energy-conserving stage</p>
<p>step 6 of energy-conserving stage of glycolysis. Each GP is converted into? </p>
<p>1, 3 diphosphoglyceric acid </p>
<p>what allows for the high energy bond on 1, 3 diphosphoglyceric acid. What enzyme aids in this reaction?</p>
<p>GP is oxidized by the transfer of two hydrogen atoms to NAD+ to form NADH.
The enzyme GP dehyrogenase couples this reaction with the creation of a high energy bond between the sugar and a phosphate. The 3 carbon sugar now has 2 phosphate groups. </p>
<p>in the 7th step of glycolysis -- after the formation of 1,3 diphosphoglyceric acid, what happens? What molecule is formed in the process?</p>
<p>The high energy P is moved to ADP to form ATP. This is the first ATP production of glycolysis via SLP
3-phosphoglyceric acid</p>
<p>in the 8th step, an enzyme does what?</p>
<p>relocates the phosphate group on 3-phosphoglyceric acid to form a high energy bond on 2-phosphoglyceric acid </p>
<p>in the 9th step \_\_\_\_\_\_ is lost, so 2-phosphoglyceric acid is converted to \_\_\_\_\_\_\_\_\_\_\_ with a \_\_\_\_\_\_ bond</p>
<p>water is lost, so it's converted into phosphoenolpyruvic acid (PEP), and the phosphate is upgraded to a high energy bond </p>
<p>the 10th step. what type of phosphorylation is occurring? what molecule is created in the process?</p>
<p>the high energy bond on phosphoenolpyruvic acid (PEP) is transferred to ADP to form ATP.
again this is SLP, and pyruvic acid is formed (3-carbon compound)</p>
<p>SLP</p>
<p>direct transfer of a phosphate group to ADP from a reactive intermediate (like PEP) generated during enzymatic conversion of one organic compound to another</p>
What is ATP made of?
nucleotide adenosine with three phosphate molecules
