BIOCHEMISTRY

catalyze the interconversion of isomers, including both constitutional and stereoisomers

catalyze cleavage without the addition of water and without the transfer of electrons; the reverse reaction (synthesis) is usualy more important

catalyze cleavage with the addition of water

catalyze oxidation-reduction reactions that involve the transfer of electrons

move a functional group from one molecule to another molecule

differ at exactly one chiral carbon

a subtype of epimers that differ at the anomeric carbon

alpha or beta conformation

have the --OH on the anomeric carbon trans o the free --CH2OH group

have the --OH on the anomeric carbon cis to the free --CH2OH

one anomeric form shifts to another, with the straight-chain form as an intermediate

basis for building complex carbohydrates and requires the anomeric carbon to link to another sugar

deoxy sugars

galactose-beta-1,4-glucose

glucose-alpha-1,4-glucose

glucose-alpha-1,2-fructose

can be used to detect the presence and quantity of various DNA strands in a sample; after electrophoresis, the sample is transferred to a membrane that can be probed with ssDNA molecules to look for a sequence of interest

pressure applied to a pure solvent to prevent osmosis and is related to the concentration of the solution 

II=iMRT

present in the pancreatic beta-islet cells as part of hte glucose sensor and is responsive to insulin in the liver

traps glucose

rate limiting step

produces F2,6-BP, which activates PFK-1

produces NADH

perform substrate-level phosphorylation

converts pyruvate to acetyl-CoA. Stimulated by insulin and inhibited by acetyl-CoA

• pyruvate--PDH-->
• acetyl-CoA (fatty acids, ketones, alcohols)
• citrate (citrate synthesis)
• isocitrate
• alpha-ketoglutarate
• succinyl-CoA
• sccinate
• fumarate
• malate
• oxaloacetate

the building of glycogen using two main enzymes:

glycogen synthase and branching enzyme

creates alpha-1,4 glycosidic links between glucose molecules

it is activated by insulin in the liver and muscles

moves a block of oligoglucose from one chain and connects it as a branch using an alpha-1,6 glycosidic link

breakdown of glycogen using two main enzymes:

glycogen phosphorylase and debranching enzyme

• removes single glucose 1-phosphate molecules by breaking alpha-1,4-glycosidic links
• --> in the liver, it is activated by glucagon to prevent low blood sugar; in exercising skeletal muscle, it is activated by epinephrine and AMP to provide glucose for the muscle itself

moves a block of oligoglucose from one branch and connects it to the chain using an alpha-1,4-glycosidic link

occurs in both the cytoplasm and mitochondria, predominately in the liver

most of gluconeogenesis is just the reverse of glycolysis, using the same enzymes

pyruvate carboxylase and PEP carboxykinase bypass pyruvate kinase

fructose-1,6-biphosphatase bypasses phosphofructokinase-1

glucose-6-phosphatase bypasses hexokinase/glucokinase

occurs in the cytoplasm of most cells, generating NADPH and sugars for biosynthesis

rate-limiting enzyme is glucose-6-phosphate dehydrogenase, which is activated by NADP+ and inhibited by NADPH and insulin

insulin secretion is high and anabolic metabolism prevails

insulin secretion decreases while glucagon and catecholamine secretion increases

dramatically increases glucagon and catecholamine secretion; most tissues rely on fatty acids

chylomicrons, VLDL, IDL, LDL, and HDL

• cholesterol may be obtained through dietary sources or through synthesis in the liver
• the key enzyme in cholesterol biosynthesis is HMG-CoA reductase

the only fatty acid that humans can synthesize

produced in the cytoplasm from acetyl-CoA  transported out of the mitochondria

beta-oxidation

ketone bodies form during a prolonged starvation state due to excess acetyl-CoA in the liver

regenerates acetly-CoA for use as an energy source in peropheral tissues

maintains blood glucose through glycogenolysis and gluconeogenesis 

processes lipids, cholesterol, bile, urea, and toxins

stores and releases lipids

conserves carbs as glycogen and uses free fatty acids for fuel

may use anaerobic metabolism, oxidative phosphorylation, direct phosphorylation (creatine phosphate), or fatty acid oxidation

uses fatty acid oxidtaion

uses glucose except in prolonged starvation, when it can use ketolysis