Exam 3 Flashcards
an inactive enzyme that must be partially digested to attain full enzymatic activity
zymogen
How does amylase digest carbohydrates?
cleaning the alpha-1,4 glycosidic bonds of starch
Which enzyme activates trypsin?
enteropeptidase
The transport of lipids in the lymph is carried out by
chylomicrons
______ pathways can be either anabolic or catabolic, depending on the energy conditions of the cell
amphibolic
ultimate acceptor of electrons in aerobic organisms
O2
the product of oxidation of carbon containing fuels in aerobic metabolism
CO2
this compound serves as an acyl carrier in metabolism
acetyl-CoA
the chemical currency of metabolism
ATP
the type of metabolism where useful energy is harvested
catabolism
serves as a reservoir of high potential phosphoric groups that can be readily transferred to ADP to regenerate ATP in vertebrate muscle
creatine phosphate
the metabolic pathways that require energy and are often biosynthetic processes are
anabolic
metabolic pathways are regulated by
- transcriptional regulation of the amount of enzyme
- allosteric control of enzyme activity
- the accessibility of substrates by compartmentalization
Explain how a metabolic pathway can contain an energetically unfavorable reaction yet still occur
the free-energy changes of the individual steps in a pathway are summed to determine the overall free-energy charge. Thus, a step that might not normally occur can be driven if it is coupled to a thermodynamically stable reaction.
What is an activated carrier? Provide two examples.
Activated carriers are molecules that are used as the carrier molecules of a particular molecule, atom, electron, or of protons. One example would be ATP, which is the activated carrier of phosphoryl groups. Flavin derivatives (FAD) and nicotinamide derivatives (NAD+) are examples of activate carriers of electrons.
stereoisomers that are mirror images of eachother
enantiomers
monosaccharides that differs at a single asymmetric carbon
epimers
the storage form of glucose in animals
glycogen
the enzymes that synthesize oligosaccharides
glycosyltransferases
the molecule to which most sugars are attached prior to transfer
UDP
a five-membered ring formed from a monosaccharide
furanose
formed when tow monosaccharides are linked together via a glycosidic bond
disaccharide
in N-linked glycoproteins, the carbohydrate portion is attached to an ____ residue in the protein
asparagine
The simplest carbohydrates are
dihydroxyacetone and D- and L-glyceraldehyde