Metabolism Flashcards
sum of all chemical reactions involved in maintaining the dynamic state of a cell or organism
Metabolism
o sum of catabolism and anabolism
Metabolism
series of biochemical reactions
Pathway
process of breaking down large molecules into smaller ones with concurrent production of energy
Catabolism
Catabolic pathway is also called the
Oxidation pathway
TRUE OR FALSE
The conversion of big biomolecules into smaller molecules is not the end.
TRUE
process of synthesizing large molecules from smaller ones.
o Anabolism
Anabolic pathway is also called the
Reducing pathway
Monosaccharides
Partial oxidation:
Complete oxidation:
Partial oxidation: CHOH
Complete oxidation: CO2 -FULLY OXIDIZED (generation of energy)
T OR F
In reduction there is generation of energy
FALSE
In Reduction there is CONSUMPTION of energy since you are forming C-H bonds in the process
2 primary biomolecules that we use for energy.
Triglycerides and polysaccharides (Carbs and Fats)
T OR F
Proteins are not sources of energy
TRUE
pathway that involves the formation of new -CH bonds
Anabolic pathway / Reducing pathway
the common metabolic cycle by which both carbs and fats would become carbon dioxide
Krebb cycle or Citric acid cycle
T OR F
There would always be reducing reaction before we can have the fully oxidized carbon dioxide
TRUE (REDOX)
What are the reducing equivalents / Reducing power
NADH+H
FADH2 (REDUCED FORMS)
Meaning electrons were taken by these forms (accepted 2 e-)
Oxidized and reduced form of the reducing equivalents
Oxidized forms
NAD+ (accepts 2 e-)
FAD (accepts 2 e-)
Reduced forms
NADH+H
FADH2
reducing equivalents / Reducing power were the consequence of the
production of carbon dioxide in the oxidation process
Would be reduced later on
A. Oxidizing agent
B. Reducing agent
A. Oxidizing agent
Would be oxidized later on
B. Reducing agent
The electron from the reduced form or the reducing equivalents will be channeled to
Electron transport chain
SEries of redox reaction happens in the
Electron transport chain
Mechanism of electron transport chain
they will create a proton reagent inside the mitochondria then the proton reagent will power the enzyme to produce ATP/ energy
What will generate more energy (ATP)?
A. Oxidative phosphorylation
B. Substrate-level phosphorylation
A. Oxidative phosphorylation
Organelles in which the common catabolic pathway takes place in higher organisms
Mitochondria
Krebb cycle happens in what part of the mitochondria
Matrix
Where replication of DNA takes place.
o Nucleus
Remove damaged cellular components and some unwanted foreign materials.
o Lysosomes
Package and process proteins for secretion and delivery to other cellular components
o Golgi bodies
The two parts to the common catabolic pathway:
o The citric acid cycle, also called the tricarboxylic acid cycle (TCA) or Krebs cycle.
o Electron transport chain and phosphorylation, together called oxidative phosphorylation.
Four principal compounds participating in the common catabolic pathway are:
o AMP, ADP, and ATP
o NAD+/NADH:
o FAD/FADH2:
o Coenzyme A; CoA or CoA-SH:
agents for the storage and transfer of phosphate groups.
o AMP, ADP, and ATP
agents for the transfer of electrons in biological oxidation-reduction reactions.
o NAD+/NADH
o FAD/FADH2:
An agent for the transfer of acetyl groups.
o Coenzyme A;
the most important compound involved in the transfer of phosphate groups.
Adenosine Triphosphate (ATP)
contains two phosphoric anhydride bonds and one phosphoric ester bond
Adenosine Triphosphate (ATP)
a nucleotide. It has a base, a sugar, and a phosphate. But the hydrolysis of this phosphate here generates for us a lot of energy. That’s it’s known as the energy currency of the cell
Adenosine Triphosphate (ATP)
a biological oxidizing agent.
Nicotinamide adenine dinucleotide (NAD+)
a two-electron oxidizing agent, and is reduced to NADH.
reduced to FADH2
NAD+
FAD
How many electrons can NAD+ and FAD can carry
2 electrons per molecule
an electron and hydrogen ion transporting molecule.
NADH
a biological oxidizing agent.
• Flavin adenine dinucleotide (FAD)
Riboflavin also refers to
FAD
it has flavin and ribitol
a two-electron reducing agent, and is oxidized to FAD.
FADH2
T OR F
Coenzyme A contains -SH sulfhydryl group
TRUE
• Like NAD+ and FAD, coenzyme A contains a unit of
ADP
• The vitamin part of coenzyme A
pantothenic acid.
• The acetyl group of acetyl CoA is bound as a
high-energy thioester.
We use this molecule to activate substances
coenzyme A
the term used to form ATP from ADP.
phosphorylation
Two types of phosphorylation
Oxidative phosphorylation
substrate-level phosphorylation
the direct transfer of a phosphate group from a substrate or metabolite in the pathway to form ATP
substrate-level phosphorylation
what is/are generated in substrate-level phosphorylation?
1 ATP
Example of substrate-level phosphorylation
glycolysis
What is/are generated in oxidative phosphorylation?
average of 2.5 ATPs
average of 1.5 FADH2
in Oxidative phosphorylation the phosphorylation in this step or reaction is coupled to the generation of
electrons in the REDOX reaction
The step/reaction does not directly transfer phosphate groups to ADP to form ATP but since it is a redox reaction, electrons from the reaction will be carried by either NAD+ (as NADH + H+) or FAD (as FADH2)
Oxidative phosphorylation
Mechanism of Oxidative phosphorylation
The electrons are brought to the inner mitochondrial membrane and transferred to the electron transport chain (ETC) where ATP is generated.
Example of oxidative phosphorylation
malic acid
What are some of the catabolic pathways that help generate energy for the cell?
Glycolysis
Beta oxidation of fatty acids from fats to TAGs (triglycerols)
Main metabolite of carbohydrates
Glucose
fructose and galactose and other forms of monosaccharide will only be converted into glucose
T OR F
Glycolysis is a anabolic pathway
FALSE
Glycolysis is a catabolic pathway
Degradation of carbohydrates/sugar
From the haworth formula, the glucose common structure resembles
which is why it’s also called
cyclic structure - pyran ring
pyranose
A series of 10 enzyme-catalyzed reactions by which glucose is oxidized to two molecules of pyruvate.
Glycolysis:
T OR F
Phosphorylation is a reversible reaction
FALSE
Irreversible reaction
First reaction of glycolysis
Phosphorylation of alpha-D-glucose
(an anomer of glucose predominant in our diet)
THIS IS AN INVESTMENT PHASE
Mechanism of the phosphorylation of alpha-D-glucose
a phosphate group from the ATP will be transferred by the enzyme hexokinase to the alpha-D-glucose (INVESTMENT PHASE)
an IRREVERSIBLE reaction
Donor: ATP
Acceptor: Glucose
Products of the first reaction
alpha-D-Glucose-6-phosphate
ADP
process of formation of glucose
Gluconeogenesis
T OR F
In gluconeogenesis the sources are glucose
FALSE
NON-CARBOHYDRATE sources
like glycerol
Second reaction of glycolysis
Isomerization of α-D-glucose 6-phosphate to α-D-fructose 6-phosphate.
Hierarchy of carbohydrates
glucose is a
fructose is a
glucose is a aldose
fructose is a ketone/ketose
difference of aldose and ketose
aldose (has aldehyde) only one functional group
ketose (has ketone) has TWO functional groups
T OR F
glucose and fructose are functional isomers of one another
TRUE
the interconversion or isomerization wherein the aldehyde is converted to ketone and it can be vice versa
tautomerism
What is the reaction 3
Phosphorylation of fructose 6-phosphate
T OR F
Phosphorylation of fructose 6-phosphate is a reversible reaction
FALSE
Irreversible reaction
The step: Phosphorylation of fructose 6-phosphate is also known as
committed step meaning this is the control/regulated region or control part of the pathway
what is the enzyme used in the Phosphorylation of fructose 6-phosphate
PHOSPHOFRUCTOKINASE
T OR F
Phosphofructokinase is a regulatory enzyme
TRUE which is why the third step is also called the control/regulated region because its influenced by substances (meaning it can be inhibited or enhanced if ATP is needed or if it’s too much already)
What is the reaction 4
Cleavage of fructose 1,6-bisphosphate to two triose phosphates.
T OR F
Cleavage of fructose 1,6-bisphosphate to two triose phosphates is reversible
TRUE
REVERSIBLE REACTION
What is the final product of glycolysis?
PYRUVATE
T OR F
DHAP is converted to pyruvate as the final product
FALSE
G3P is converted to pyruvate
DHAP is converted to G3P
What is converted in the isomerization of the triose phosphate
Dihydroxyacetone (DHAP) –> G3P
Anaerobic glycolysis product
lactate
REDUCTIVE
Aerobic oxidation product
6 CO2 and 6 H2O
Anaerobic alcoholic fermentation products
2 CO2 and 2 ethanol
REDUCTIVE
responsible for the conversion of pyruvate to acetyl-coa
dehydrogenase complex (overall reaction)
Products of the pyruvate dehydrogenase complex
ACETYL-COA
CO2
NADH+H+
pyruvate dehydrogenase complex happens in the
mitochondrion
Mitochondrial matrix
glycolysis happens in the
cytosol
T OR F
TCA cycle is amphibolic
TRUE
the pathway plays a role in both catabolism and anabolism.
Why is the kreb’s cycle also called the tricarboxylic acid cycle?
BEcause of the Step 1
production of CITRATE which has 3 carboxyl groups in the citric acid
T OR F
Citrate and aconitate are achiral; neither has a stereocenter.
TRUE
which is why in the second step it will be transformed into isocitrate which is chiral
T OR F
Citrate have 2 stereocenters and 4 stereoisomers are possible
FALSE
ISOCITRATE HAVE 2 stereocenters and 4 stereoisomers are possible
1 NADH+H+ is equivalent to how many ATP after ETC
2.5 or 3 ATPs
1 FADH2 is equivalent to how many ATP after ETC
1.5 or 2 ATPs
