Learning Outcomes Chapter 5 Flashcards
Define Metabolism
Collection of controlled biochemical reactions that take place within a microbe
The ultimate function of metabolism is to reproduce the organism.
Define the Catabolic pathway; give an example.
Break larger molecules into smaller products.
(Polymonomers to monomers)
Exergonic (energy release)
example - Cellular Respiration
Define the Anabolic pathway; give an example.
Synthesize large molecules from the smaller
products of catabolism
Endergonic (require more energy than they
release)
ex - Photosynthesis
Define Oxidation and Reduction reactions.
Transfer of electrons from an electron donor to an electron acceptor
Reactions always occur simultaneously.
Cells use electron carriers to carry electrons (often in
H atoms)
What are the three types of electron carriers?
Nicotinamide adenine dinucleotide (NAD+)
Nicotinamide adenine dinucleotide phosphate
(NADPH)
Flavin adenine dinucleotide (FAD)
NAD+
Reduced to NADH –
When?
▪ Glycolysis
▪ Synthesis of Acetyl-CoA
▪ Krebs Cycle
FAD
Reduced to FADH2
– When?
▪ Krebs Cycle
In the presence of the
final electron acceptor
NADH and FADH2 will?
Oxidized to NAD+ and
FAD
–When?
▪ Electron Transport Chain
Describe the structure of ATP.
Adenosine triphosphate is made of:
Adenine, ribose, and three phosphate groups
ATP in Substrate-Level
Phosphorylation?
How ATP is made - A high-energy
phosphate from a pathway intermediate is
transferred directly to ADP to make ATP
Electron transport chain used? No
Used in? Glycolysis, Krebs cycle,
fermentation
Cell types that use it - Prokaryotic and
eukaryotic
ATP in Oxidative Phosphorylation?
How ATP is made - ADP is recharged to ATP using electron transport chains powered by nutrients.
Electron transport chain used? Yes
Used in - Aerobic and anaerobic electron transport chains of cellular respiration
Cell types that use it - Prokaryotic and
eukaryotic
Explain the naming enzyme and its classification based on the site of action, type of action
and rate of enzyme production
The names of enzymes usually end with the suffix -ase, and the name of each enzyme often incorporates the name of that enzyme’s substrate, which is the molecule the enzyme acts on. Based on their mode of action, enzymes can be grouped into six basic categories.
Hydrolases
Isomerases
Ligases, or polymerases
Lyases
Oxidoreductases
Transferases
Define enzyme
Organic catalysts that speed up chemical reactions. Lower energy is required.
Define substrate
A substrate is a molecule that an enzyme reacts with
Describe the parts or components of a holoenzyme and RNA enzymes.
Holoenzyme - The binding of an apoenzyme (Apoenzyme are inactive if not bound to nonprotein)
and its cofactor (inorganic ions or coenzymes) forms an active enzyme called a holoenzyme
Ribozymes - RNA molecules functioning as enzymes.
Define activation energy, enzyme, apoenzyme, cofactor, coenzyme, active site, and
substrate, and describe their roles in enzyme activity
Activation energy - The amount of Energy needed for a chemical reaction.
Apoenzyme - Apoenzyme are inactive if not bound to nonprotein.
Cofactor - inorganic ions or coenzymes
Coenzyme - Organic cofactor
Active site - The functional sites of an enzyme and its substrate. The shape of an enzyme’s functional site
Substrate - A substrate is a molecule that an enzyme reacts with
Describe three stages of aerobic glucose catabolism (glycolysis, the Krebs cycle, and an electron transport chain), including their substrates, products, and net energy production.
Glycolysis - glucose ultimately breaks down into pyruvate and energy; a total of 2 ATP is derived in the process (Glucose + 2 NAD+ + 2 ADP + 2 Pi –> 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP + 2 H2O).
Krebs cycle - Oxidation of citric acid (formed from acety CoA-oxaloacetic acid reaction) produces NADH, FADH2, and ATP Oxidation of molecules liberates electrons for an electron transport chain (ETC)
Using as ETC, ATP is generated by oxidative phosphorylation.
Electron Transport Chain - NAD+, FAD, water, and ATP.
Describe the role of acetyl-CoA, the Krebs cycle, and the electron transport chain in carbohydrate catabolism
acetyl-CoA stores a large amount of petential energy which is released step by step in the Kreb cycle. Pyruvic acid cannot enter the Kreb cycle directly so it’s coverted to acetyl-CoA thru decarboxylation.
Contrast electron transport in aerobic and anaerobic respiration.
Aerobic respiration uses oxygen.
Anaerobic respiration is respiration without oxygen; the process uses a respiratory electron transport chain but does not use oxygen as the electron acceptor.
Identify four classes of carriers in electron transport chains
Flavoproteins
ubiquinones
metal-containing proteins
cytochromes
