Chapter 5 Flashcards
The bond between two sugar molecules is called what?
Glycosidic linkage (they are named based on where they & how they are linked)
The hydrolysis of polysaccharides into monosaccharides is favored _________________
Thermodynamically
Enzymes that are used in the hydrolysis of polysaccharides into monosaccharides are named how?
Based on the sugar that they hydrolyze (ex. Maltase breaks maltose into two glucose)
Humans & other mammals can’t break down Beta linkages but we can break down lactose due to the enzyme __________ which can digest lactose
Lactase
The oxidation of glucose is accompanied by what?
NAD+ & FAD where during redox reactions they form NADH & FADH2
__________ is required for activation of adenylate cyclase by cholera toxin & _______ can associate with a protein to become a flavoprotein
NAD+, FAD
What is the 4- step process that is used to oxidize glucose?
- Glycolysis
- The pyruvate dehydrogenase complex (PDC)
- The Krebs cycle
- Electron transport/oxidative phosphorylation
In _____________ (glucose splitting) the glucose is partially oxidized while it is spilt in half into two identical pyruvic acid molecules
Glycolysis
Glycolysis occurs in the ____________ & does require oxygen
Cytoplasm
In PDC the pyruvate produced in glycolysis is decarboxylated to form an _________ group where that group is then attached to coenzyme A which carries it into the Krebs cycle (small amounts of NADH is produced)
Acetyl group
In the Krebs cycle (critic cycle) the acetyl group from PDC is added to oxaloacetate to form _________ acid. The PDC & Krebs cycle occurs in the matrix
Citric acid
In electron transport/oxidative phosphorylation, the high energy electron carried by NADH & FADH2 is oxidized by the ____________ in the inner mitochondrial membrane.
Electron transport chain
In ___________ a glucose molecule is oxidized and split into two pyruvate molecules, producing a net surplus of 2 ATP(from ADP + P(i) & producing 2 NADH (from NAD+ + H+)
glycolysis
What is the formula for glycolysis?
Glucose + 2 ADP + 2P(i) + 2NAD+ —> 2 Pyruvate + 2ATP + 2NADH + 2H2O + 2H+
Hexokinase
Catalyzes the first step in glycolysis, the phosphorylation of glucose to G6P. G6P feedback-inhibits hexokinase
_________ is produced in only one step: when an aldehyde (-de) is oxidized to a COOH (-ate) (in glycolysis)
NADH
_______ is converted to ADP in (in glycolysis) every time a phosphate is added to a substrate & ADP is made into ATP every time a phosphate comes off a substance
ATP
Phosphofructokinase (PFK)
Catalyzes the 3rd step which is the transfer of a phosphate group from ATP to fructose-6-phosphate to form fructose -1,6-bisphosphate (F1,6bP)
Under aerobic conditions (presence of oxygen) the pyruvate produced in glycolysis enters the PDC and Krebs cycle to be oxidized completely to ______
CO2
In ___________ conditions (without oxygen) , electron transport can not function and the limited supply of NAD+ becomes entirely converted to NADH
Anaerobic
Fermentation
Has evolved to regenerate NAD+ in anaerobic conditions thereby allowing glycolysis to continue in the absence of oxygen
Oxidative decarboxylation
Is a reaction in which a molecule is oxidized to release CO2 and produce NADH
In _________________ pyruvate is changed from a 3- carbon molecule to a 2-carbon molecule while CO2 is given off and NADH is produced
Oxidative decarboxylation
The PDC changes pyruvate into an activated _________ unit
Acetyl
An activated Acetyl means the Acetyl attached to a carrier called _____________
Coenzyme A
Prosthetic group
When a cofactor is very tightly or covalently bound to the enzyme
Krebs Cycle
Is a group of reactions which take the 2-carbon acetyl unit from acetyl - CoA combine it with oxaloacetate & release two CO2 molecules (NADH & FADH2 are produce in the process)
In the first stage of the Kreb cycle what happens?
Oxaloacetate (OAA) & acetyl-CoA react together to form citric acid (citrate)
On stage 2 of the Krebs cycle _________ is further oxidized to release CO2 & to produce NADH from NAD+ with oxidative decarboxylation
Citrate
The oxidation of glucose has created what?
- 2 ATP and 2 NADH per glucose molecule in glycolysis
- Pyruvate dehydrogenase: 2 NADH per glucose (one per pyruvate)
- Krebs cycle: 6 NADH, 2FADH2, & 2 GTP per glucose
What are the two goals of electron transport/oxidative phosphorylation?
- Reoxidize all the electron carriers reduced in glycolysis, PDC, and the Krebs cycle
- Store energy in the form of ATP in the process
Oxidative phosphorylation
Is the oxidation of the high energy electron carriers NADH &FADH2 coupled to the phosphorylation of ADP to produce ATP
Electron - transport chain
Is a group of five carbon electron carriers
ATP synthase
A large protein complex which contains a proton channel that spans the inner membrane
The committed step in glycolysis
The conversion of F6P to F1, 6bP with the PFK enzyme is the first committed step in glycolysis
The two goals of electron transport/oxidative phosphorylation are what?
- Reoxidize all the electron carriers reduced in glycolysis, PDC, & the krebs cycle
- Store energy in the form of ATP in the process
Oxidative Phosphorylation
Is the oxidation of the high-energy electron carrier NADH & FADH2 coupled to the phosphorylation of ADP to ATP
The electron-transport chain
Is a group of five electron carriers
Beta linkages is when the oxygen on carbon one is ________ & alpha linkage is when its ________
Up, down
The enzyme used in the hydrolysis of linkages are named by the ___________ they hydrolyze
sugar
Glycolysis produces what?
2 pyruvate molecules , ATP, & NADH (doesn’t require oxygen)
________ is however need for the first few steps o f glycolysis
ATP
Fermentation
Regenerates NAD+ in anaerobic conditions so that glycolysis can continue in anaerobic conditions (pyruvate turning into lactate)
Excess lactate build goes through the _________ cycle
Cori
The energy released through oxidation of NADH & FADH2 by the electron transport chain (source of energy to drive the phosphorylation of ADP to ATP) is used to pump out of the _______________ & into the intermembrane space
Mitochondrial matrix
The electron-transport chain is a group of ______ large electron carriers & each member reduces the next member down the line (& some small molecules)
5
The 1st large carrier in the electron transport chain is _____________________________
NADH dehydrogenase (coenzyme Q reductase)
NADH dehydrogenase passes its electron to ___________________________
Ubiquinone (Coenzyme Q) (not part of the 5 large member its a small one)
Ubiquinone passes its electron to ___________________________ (small molecule) where it passes its electron to ___________________________ (large member) where it then passes its to the last member which is _____________________ (large member)
Cytochrome C reductase, Cytochrome C, Cytochrome C oxidase
The end product of the electron transport chain is ________
H2O (Cytochrome passes its electrons to O2reducing it to H2O)
The pentose phosphate pathway (PPP) diverts glucose 6 phosphate from glycolysis to form _________________, ribose 5-phosphate, & glycolytic intermediates
NADPH
The first enzyme in the PPP is _____________________________ & its the primary point of regulation
Glucose 6-phosphate dehydrogenase (G6PDH)
In the PPP its product NADPH acts via ______________ feedback to inhibit G6PDH
Negative
