Intro to Metabolism Flashcards
The overall process through which living systems acquire and use energy to carry out various functions.
Metabolism
The degradation of nutrients and cell components to salvage components and/or generate energy.
Catabolism
The biosynthesis of biomolecules from simpler molecules.
Anabolism
What are the intermediates in metabolic pathways called?
Metabolites
Which type of metabolism carries out exergonic oxidation of nutrients?
Catabolism`
What drives anabolic reactions?
The energy derived from catabolic reactions
What class of enzymes catalyze oxidation/reduction reactions in metabolism?
Oxidoreductases
What classes of enzymes catalyze group transfer reactions in metabolism?
1) Transferases
2) Hydrolases
What classes of enzymes catalyze elimination, isomerization, and rearrangement reactions in metabolism?
1) Isomerases
2) Mutases
What classes of enzymes catalyze carbon-carbon bond breaking or formation reactions in metabolism?
1) Hydrolases
2) Lyases
3) Ligases
What are the products of the Citric Acid Cycle (TCA)?
1) CO2
2) NADH and FADH2
What are the reduced enzymes (products of the TCA) that drive electron transport and oxidative phosphorylation?
NADH and FADH2
What are the products of oxidative phosphorylation?
1) ATP
2) NAD+
3) FAD
4) H20
What are metabolic reactions controlled by? What guarantees the efficiency of reactions?
Enzymes; the enzymes guarantee efficiency by preventing useless or toxic by-products.
What allows different metabolic pathways to occur at the same time?
The pathways are compartmentalized.
What types of proteins are necessary for metabolism due to the compartmentalization of metabolic pathways?
Transport proteins
In what organelle does the Citric Acid Cycle, electron transport, oxidative phosphorylation, fatty acid oxidation, and amino acid break-down take place?
Mitochondrion
Where does glycolysis, the pentose phosphate pathway, fatty acid biosynthesis, and many reactions of gluconeogenesis take place?
The cytosol of the cell
In which organelle does enzymatic digestion of cell components and ingested material take place?
Lysosome
In which organelle does DNA replication and transcription and RNA processing take place?
Nucleus
In which organelle does post-translational processing of membrane and secretory proteins and formation of plasma membrane and secretory vesicles take place?
Golgi apparatus
In which organelle does synthesis of membrane-bound and secretory proteins take place?
Rough ER
In which organelle does lipid and steroid biosynthesis take place?
Smooth ER
In which organelle do oxidative reactions carried out by amino acid oxidases and catalases take place?
Peroxisome
What are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. These enzymes usually display different kinetic parameters (e.g. different KM values), or different regulatory properties.
Isoenzymes
What is a larger than normal level of LDH-1 (lactate dehydrogenase-1) in blood indicative of?
A heart attack
Where is the M type of LDH normally found?
Anaerobic tissue (skeletal muscle and liver-take pyruvate to lactate)
Where is the H type of LDH normally found?
Aerobic tissues (heart-take lactate to pyruvate)
What enzyme catalyzes the reaction of pyruvate to lactate (and vice-versa)?
LDH (lactate dehydrogenase) (M type takes pyruvate to lactate, H type takes lactate to pyruvate)
Where does protein enter the metabolic pathway?
At pyruvate, Acetyl CoA, and the TCA cycle
Where do triacylglycerides enter the metabolic pathway?
AT pyruvate and acetyl CoA
Where does Galactose enter glycolysis?
At G6P
Where does Fructose from liver enter glycolysis?
At DHAP and GAP
Where does fructose from adipose tissue enter glycolysis?
At F6P
What are the electron carriers for catabolism?
NADH and FADH2
What is the electron carrier for anabolism?
NADPH
What are the reactants and products of homolytic fermentation?
Reactants = pyruvate and NADH Products = pyruvate and NAD+
