Chapter 15 Respiration and Photosynthesis

Biology, 7th Edition (Book & CD-ROM)

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 9 I. Stages of Cellular Respiration A. Glycolysis 1. Technically it isn’t a part of celluar respiration (doesn’t require oxygen), but energy is derived from glucose in this process to produce the starting material for the citric acid cycle 2. Occurs in the cytosol 3. Breaks down glucose into two pyruvate molecules B. Citric Acid Cycle 1. Takes place in the mitochondrial matrix 2. Oxidizes a derivative of pyruvate to carbon dioxide C. Oxidative Phosphorylation 1. You have NAD + . Then enzymes transfer electrons from different substrates to the NAD + . It accepts 2 electrons and 1 proton, making NADH. II. Glycolysis (splitting of sugar) Glucose is split into 2 3-carbon sugars which are oxidized and rearranged to form pyruvate A. Step 1 1. Glucose enters the cell 2. Is phosphorylated by the enzyme hexokinase a. Transfers a phosphate group from ATP to the sugar 3. Glucose becomes Glucose-6-phosphate (phosphate on the 6 th carbon) B. Step 2 1. Glucose 6 phosphate is rearranged into its isomer, fructose-6-phosphate 2. Enzyme used is isomerase C. Step 3 1. Phosphofructokinase transfers a phosphate group form ATP to the sugar 2. Now it’s Fructose-1,6-biphosphate D. Step 4 1. Aldolase breaks up the sugar molecule into two different 3-carbon molecules a. Dihydroxyacetone phosphate and glyceraldehydes-3-phosphate b. They are both isomers of eachother E. Step 5 1. Isomerase converts dihydroxyacetone phosphate to glyceraldehydes-3- phosphate 2. Glyceraldehydes is the one of the two that moves on to the next half of glycolysis, so it is the only important one F. Step 6 1. Sugar is oxidized by the transfer of 2 electrons and a proton to NAD + making NADH. a. Exergonic b. Enzyme (triose phosphate dehydrogenase) uses the released energy to attach phosphate group to molecule i Molecule of very high potential energy G. Step 7 1
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1. The phosphate group that was added in the previous step is transferred to ADP in an exergonic reaction, and 2 ATP are produced by phosphoglycerokinase. It is converted to 3-phosphoglycerate
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

Chapter 15 Respiration and Photosynthesis - Chapter 9 I....

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online