大致的情况(2005~2009年)
Peptide unit（plane）(
0次)
The partial double-bond character of the peptide bond makes Cα1, C, O, N, H, Cα2 six atoms coplanar（共面的）, Cα1 and Cα2 are trans to each other, this semi-rigid plane composed of those six atoms is termed as peptide unit.
Motif（
5次）
Motifs are the assembling of more than 2 secondary structural elements that fold to near each other in space and have special functions. Some motifs consist of only a few conserved functionally important AAs rather than secondary structures
e.g. RGD (Arg-Gly-Asp ) motif
domain（
2次）
The tertiary structure of some proteins can be divided into 2 or more relatively independent compact regions that may be joined by a flexible弯曲的 segment片段 of the chain, and have special functions. These compact units called domains
Isoelectric point（
0次）
pI is the pH at which protein molecular becomes electrically neutral电中性, has no net electric charge
Denaturation of protein （
3次）
Protein spatial structure is sensitive to denaturing agents (high T, urea, strong acids or bases, organic solvents有机溶剂, detergents洗涤剂, heavy metal ions)
These agents result in unfolding and disorganization of protein spatial structure without change in primary structure, and associate with loss of biological activity
Enzymes（
0次）
Enzymes are highly efficient biocatalysts which are involved in almost all biological reaction.
Enzymes are proteins in chemical nature . They have special conformation and can be denatured
Some RNA/DNA have enzyme activity, which are called Ribozymes核酶
Active site (center) of enzyme（
3次）
-- active center, catalytic site
-- Active site is a three-dimensional, local region of the enzyme, the region is composed of several essential groups of AAs, that has special spatial structure which specifically binds substrate and catalyzes it to become product
-- coenzymes or prosthetic groups can be involved in active site
Allosteric regulation （
4次）
small allosteric effectors, which generally have little or no structural similarity to the substrate, binding to allosteric site of the enzyme by non-covalent bonds triggers changes in enzyme conformation, then alter the catalytic capacity of the enzyme.
binding of allosteric effector to allosteric site
can change the E conformation and activity
(activation or inhibition)
allosteric regulation is a fast effect
An allosteric activator increases the enzyme
activity, while an allosteric inhibitor decreases
the enzyme activity.
Covalent modification（
2次）
The structure and activity of many enzymes can be altered reversibly（可逆性改变） through covalent modification by another enzyme
the most common modification:
phosphorylation磷酸化 / dephosphorylation--- addition and removal of a phosphate group
Fast control of enzyme activity
Isozymes (同工酶) （0次）
Isozymes(isoenzymes): one group of enzymes
Catalyze催化 the same reaction
have different protein structure, physic-chemical and immunological properties 免疫学性质
present in the same species物种, the same individual单独 body or same cell,
encoded 编码by different genes or the same gene
Zymogen and activation of zymogen（
1次）
(1) Some enzymes are synthesized and secreted as large inactive precursors called zymogens or proenzymes
(2) Zymogens are activated by the irreversible hydrolysis one or more peptide bonds and forming or exposing the active site in the E molecule
Glycolysis (糖酵解) （
0次）
1 glucose is converted to 2 lactate in anaerobic condition.
2ATPs are produced in this pathway
Gluconeogenesis糖异生（
1次）
The glucose or glycogen molecules can be produced in liver from non-carbohydrate such as lactate, pyruvte, amino acid and glycerol largely through reverse pathway of glycolysis .This pathway is called…..
The main site of gluconeogenesis is liver (90%). Kidney provide 10% of newly synthesized glucose molecules.
substrate-level phosphorylation （
0次）
The transfer of the high-energy phosphoryl group of high- energy substrate (eg. glycerate-1,3-bisphosphate) to ADP, then ATP is formed.
The corti cycle（
1次）
Cori cycle is a mechanism for meeting the glucose needs at exercise. Muscles at work produce lactate from glycolysis when oxygen becomes limiting. Lactate is transported from the muscles to the liver via the bloodstream. In the liver, lactate is converted (gluconeogenesis) back to glucose, where it is dumped back into the bloodstream for transport to muscle.
Mobilization of triacylglycerol（
1次）
Triacylglycerols stored in adipose tissue are hydrolyzed, the products glycerol and fatty acid are transported to the tissues, in which fatty acids can be oxidized for energy production. The principal enzyme in mobilizing stored fat is triglyceride lipase, which is hormone-sensitive TG lipase(HSL).
b-Oxidation of fatty acids（
5次）
In the matrix of mitochondrion, fatty acyl-CoAs
are oxidized in a series of cycles that each cycle
release two carbons from the carboxyl in the form of acetyl-CoA. Each cycle involves four reactions-dehydrogenation, hydration, dehydrogenation, and thiolytic cleavage.
Ketone body（
0次）
Ketone bodies include acetoacetate, acetone, and β-hydroxybutyrate. They are intermediates of FA oxidation, formed in mitochondria of liver and exported to extrahepatic tissues to be oxidized and utilized.
Overproduction results in ketoacidosis
Biological oxidation（
0次）
The oxidation taking place in organism is termed biological oxidation. It mainly refers to the enzymatic steps in the oxidative degradation of carbohydrates, fats, and amino acids to CO2 , H2O and energy. Some of the energy is used for the generation of ATP from ADP and Pi, and the other is released as heat energy.
Respiratory chain （
0次）
(electron transfer chain)
Definition:
The mitochondrial respiratory chain consists of a series of enzymes with prosthetic groups capable of accepting and donating either one or two electrons, most of which are membrane-bonded proteins. Each component of the chain can accept electrons from the preceding carrier and transfer them to the following one, in a specific sequence
Definition of Oxidative Phosphorylation: （
7次）
The process of the enzymatic phosphorylation of ADP to ATP coupled to electron transfer from a substrate to molecular oxygen is termed Oxidative phosporylation.
P/O ratio（
0次）
The efficiency of oxidative phosphorylation is determined by the P/O ratio, which is a measure of the molecules of ATP made per mol oxygen atom consumed (per pair of electrons carried through the electron transport)
essential amino acids：（
0次）
Some of amino acids that can not be synthesized by human , must be obtained in the diet to meet body’s metabolic needs.they are called essential amino acids.(8 kinds )
The putrefaction of protein（
2次）
After the absorption of most of protein, intestinal bacterial activity act on the residue passed into the large intestine, that is called putrefaction of protein. Most of the producer of the putrefaction of protein are harmful to human beings, for example: amine, ammonia, phenol, indole and sulfureted hydrogen.
alanine - glucose cycle: （
1次）
anima acids in human being’s muscles transfer their amino groups to pyruvic acid and form alanine through transamination. Then alanine come into blood and is transported to the liver. In the liver alanine put off amino group which is used to compose urea The other producer pyruvic acid is converted to glucose which can be transported to the muscle through blood. In the muscle, glucose is converted to pyruvic acid through glycolytic pathway, which again can accept amino group to form alanine. This cycle is called alanine-glucose cycle. The significances of Glucose-alanine cycle include：
1. To transport ammonia in the nontoxic forms of alanine from muscles to liver.
2. To regulate blood glucose indirectly and to supply available pyruvate for muscles.
.Metabolism of one-carbon unit（
7次）
Definition: One-carbon units produced by AA catabolism and carried by tetrahydrofolate are called one-carbon unit
Types: methyl (-CH3) group
methylene (-CH2-) group
methenyl (-CH=) group
formyl (-CHO) group
formimino (-CH=NH) group
Allosteric regulation: （
4次）
Some molecules called effectors can bind noncovalently at a site other than the active site and can alter the affinity of the enzyme for its substrate or modify the maximal catalytic activity of the enzyme or both.
Negative effectors ( allosteric inhibitors)
Positive effectors ( allosteric activitors)
covalent modification（
2次）
Some groups on apoenzyme can be catalyzed by other enzymes, occuring reversible covalent modification then change the enzyme activity.
phosphorylation and dephosphorylation
Methylation and demethylation
Acetylation or deacetylation
Adenylation or deadenylation
SH or -S-S
Biotransformation of liver （
3次）
Definition:
The nonnutrition substances are converted to more polar metabolites by various chemical reaction ,and then promoted their excretion from the body. This process is called biotransformation.
exogenous compounds (Xenobiotics) are chemical compounds foreign to the body,such as drugs,food additives, toxicity,and environmental pollutants ,etc.
endogenous compounds such as homone, neurotransmitter, amines ；ammonia，putrefactional prodacts etc.
Enterohepatic circulation of bile acid（
1次）
Bile acids are carried from the liver through bile ducts to the gallbladder, Then bile acids is secretion into the intestine, where they aid in the emulsification of dietary lipids. the bile acids are reabsorbed (passive and active)in the lower small intestine, and returned to the liver for reuse through the portal vein.
. This process is termed the enterohepatic circulation.
2，3-BPG（
1次）
[ 此帖被紫色妖姬在2009-04-25 13:43重新编辑 ]
