Week 1 - Basic Concepts Flashcards
What reaction cleaves a bond within a molecule and
adds water elements?
Hydrolysis
What reaction forms a bond between hydroxyl
groups of 2 molecules and expels water?
Condensation
Why is carbon well-suited to life?
Small, provides 4 covalent bonds, binds various functional groups. Can form linear and branched chains, and rings.
List (in order most to least) the 4 main elements in the
human body.
Hydrogen, Oxygen, Carbon, Nitrogen
What term is used to describe molecules that have
both polar and nonpolar regions?
Amphipathic
Allosteric Control
The regulation of an enzyme by a regulatory molecule that interacts at a site (allosteric site) other than the active site (at which catalytic activity occurs).
Allosteric Modulator
A substance which indirectly influences (modulates) the effects of a primary ligand that directly activates or deactivates the function of a target protein (can be positive or negative influence).
Isoenzymes
Each of two or more enzymes with identical function but different structure. Both catalyse the same reaction, and multiple final products feed back to both enzymes.
How does phosphorylation / dephosphorylation affect the activity of enzymes?
It regulates them. Phosphorylation may switch an enzyme on, whilst dephosphorylation may switch an enzyme off.. Alternatively, it may switch them off and on, respectively.
Zymogens
Inactive precursors that become
active following cleavage, eg trypsinogen to trypsin.
Name the 3 general factors affecting the activity of
enzymes.
Amount
Catalytic Activity
Accessibility of substrates
State the concept used for regulation of an enzyme by
a regulatory molecule that interacts at a site other
than the active site?
Allosteric Control
What is the underlying principle of metabolic pathways
Fuels are degraded and large molecules are constructed in a series of reactions.
What does oxidation do in regards to ATP?
Fuels its formation.
What is a metabolic pathway?
A linked series of chemical reactions occurring within a cell. The reactants, products, and intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical reactions catalyzed by enzymes.
The three forms of energy in biology?
- Energy carriers
- Macromolecules (highly reduced molecules eg food)
- Electrochemical gradients, ie electrical force (membrane potential) and chemical force (ion concentrations).
The three parts of an ATP molecule?
An adenine molecule (a purine structure - double ring), a ribose sugar, and three phosphate groups linked together (triphosphate). Note that adenine together with the ribose are called adenosine.
What do NADH, NADPH, and FADH2 stand for?
Nicotinamide adenine dinucleotide.
Nicotinamide adenine dinucleotide phosphate.
Flavin adenine dinucleotide.
What do the electron carriers do?
Act to shuttle electrons and H+ between anabolic and
catabolic processes. Also act as cofactors for many enzymes.
What is the difference between NADH and NADPH?
No effect on the electron-carrying properties, but allows NADPH to bind different substrates compared to NADH. NADPH is mainly used in the synthesis of organic molecules, whereas NADH is mainly used in ATP generation.
Which vitamin are NADH and NADPH derived from?
Vitamin B3 (Niacin).
What is Coenzyme A?
An activated carrier of acyl groups, its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidized for energy production.
Oxidation of organic molecules is important for
energy production. True or false?
True.
A loss of a C-H bond from an organic molecule is
indicative of what process?
Oxidation.
