Biochemistry Flashcards
What are the 4 monosaccharides?
Glucose, fructose, mannose, and galactose.
These can not be broken down into smaller forms.
How are monosaccharides classified?
By the number of carbons they contain.
What is the importance of Galactose
It can be changed to glucose in the liver and metabolized. Synthesized in the mammary gland to make lactose of milk. A constituent of glycolipids and glycoproteins.
What is the importance of fructose?
It can be changed to glucose in the liver and intestine and so used in the body.
What is the clinical importance of fructose?
Hereditary fructose intolerance leads to fructose accumulation and hypoglycemia.
What is the clinical importance of galactose?
Failure to metabolize leads to galactosemia and cataract.
What are the 4 disaccharides?
Sucrose, maltose, lactose, and isomaltose.
How are disaccharides bound?
By a glycosidic linkage.
What is a glycosidic linkage?
A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate.
What is the composition of maltose?
What kind of bond is maltose?
Glucose + glucose.
alpha1-4.
What is the composition of lactose?
What kind of bond is lactose?
Galactose + glucose.
Beta1-4.
Usually, we can not break down beta bonds but lactase can.
What is the composition of sucrose?
What kind of bond is Sucrose?
Glucose + fructose.
Alpha1-Beta2
What are the 4 types of polysaccharides?
Glycogen - made up of large chain molecules. It is a readily mobilized storage form o glucose.
Cellulose - The major component in the rigid cell walls in plants is cellulose. Cellulose is a linear polysaccharide polymer with many glucose monosaccharide units.
Starch - is formed by the condensation of amylose and amylopectin.
Inulin - naturally occurring polysaccharide most often extracted from chicory. The inulins belong to a class of dietary fibers known as fructans. Inulin is used by some plants as a means of storing energy and is typically found in roots or rhizomes
What are enlongase and desaturase used for?
Used to change from lower/smaller FAs to longer/higher FAs.
What is cardiolipin?
A phospholipid in mitochondria (inner membrane) required for the functioning of the phosphate transporter and for cytochrome oxidase activity,
Where is cholesterol primarily synthesized?
In the liver.
Where does cholesterol synthesis occurs in the cell?
Cytoplasm.
What is cholesterol?
Cholesterol is an organic molecule. It is a sterol, a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. It is a yellowish crystalline solid.
Component of all cell membranes.
Precursor of bile acids, steroid hormones, and vitamin D.
What are the names of the different forms of fats?
Saturated, unsaturated, trans fats, monounsaturated, and polyunsaturated.
What receptors do they bind to in the receptors of the hepatic tissue?
Chylomicron (Apo-E) receptor.
What does APOE bind to?
ApoE binds to VLDL and HDL3 particles by a two-step mechanism with the rate being influenced by the stability and ease of unfolding of the N-terminal helix bundle domain.
The chylomicron binds to the ApoE receptor and deposits fat into the free cholesterol pool. The lipid is re-esterified into the VLDL - LDL family.
Where is the LDL is made?
What receptor does it bind to?
Made by the liver.
It binds to the apoB-100 receptor
Why is HDL “good”?
Because it has the ability to change or exchange cholesterol ester or triglyceride. As triglyceride is taken away from a molecule, that molecule becomes less oxidizable. The activity of HDL is to increase the safety of the circulating IDLs, LDL, and VDLs
How much energy do we get from burning fat?
129-131 ATP from 16 carbon fatty acids.
How do we make cholesterol vs ketones vs energy?
Depends on which enzymes are used for which purpose.
Why is acetoacetyl CoA important?
Because it is the intermediate between acetyl CoA for energy in beta-oxidation and the formation of HMG CoA.
Why is HMD CoA important?
Because it is the parent for ketone body formation and cholesterol formation.
What do we do with acetoacetyl CoA between the formation of either ketone or cholesterol?
The enzyme we use makes the difference.
HMG-CoA synthase is synthetic to HMG-CoA.
HMG-CoA Lyase is what starts the conversion of HMG-CoA into ketones.
HMG-CoA reductase is what starts the conversion of HMG-CoA into cholesterol.
What does delta24 Reductase do?
Converts desmosterol into cholesterol.
What is CoQ-10 dependent on?
Mevalonate
or
Sidechain from the cholesterol formation.
What does hormone-sensitive lipase do?
Breaks the fat out of the adipose cells, breaks triglycerides into glycerol and free fatty acids, and exports free fatty acids.
Why is carnitine important?
Without it, we can not shuttle the fat into mitochondria for beta-oxidation and energy production.
What are the essential amino acids?
Phenelanine, valine, threonine, tryptophan, methionine, histidine, Arginine, Lysine, and Leucine.
PVT TIM HALL
Amines function
Structural and biogenic.
What is glutathione
It is a substance made from the amino acids glycine, cysteine, and glutamic acid.
What do enzymes do?
Speed up and already thermodynamically reaction by lowering the energy of activation.
Enzyme must bind to a substrate.
Enzyme is NOT part of any product.
What are cofactors?
Small molecular weight substances (B-vitamins and trace minerals) that are needed to help some enzymes react.
What is glycolysis?
The breakdown of glucose by enzymes, releasing energy (ATP) and pyruvic acid.
Glucose -> 2 pyruvate molecules
Where does glycolysis happen?
In the cytosol of cells.
What is glucose?
A simple sugar which is an important energy source in living organisms and is a component of many CHO.
It is a 6 carbon sugar.
It is the most abundant monosaccharide.
What would be the cause(s) of high glucose in the blood?
Hyperglycemia is a defining characteristic of diabetes - when the blood glucose level is too high because the body isn’t properly using or doesn’t make the hormone insulin.
You get glucose from the foods you eat.
What is a good blood sugar level for prediabetes?
This measures your blood sugar after an overnight fast (not eating). A fasting blood sugar level of 99 mg/dL or lower is normal, 100 to 125 mg/dL indicates you have prediabetes, and 126 mg/dL or higher indicates you have diabetes
How is glycolysis divided?
It is divided into two phases: Energy consuming phase and energy producing phase.
What happens after glucose amounts risen in the blood?
Insulin is secreted by the pancreas (Beta-islet cells) to regulate the amount of glucose in the body.
How does glucose get inside the cells?
Through glucose transporters such as GLUT2 (liver and pancreas).
What is the rate-limiting enzyme in glycolysis?
Phosphofructokinase.
What activates phosphofructokinase?
AMP, fructose 2,6-biphosphate, and insulin.
What inhibits phosphofructokinase?
ATP, citrate, and glucagon.
What down-regulates pyruvate?
ATP and alanine.
What up-regulates pyruvate?
Fructose 1,6-Biphophate.
Is glycolysis aerobic or anaerobic?
Anaerobic.
How much ATP is generated per glucose?
32-36
What cycle is aerobic?
Krebs cycle.
Do red blood cells have mitochondria?
No, they do not have mitochondria.
What is the Krebs cycle interchangeably called?
Citric acid cycle
What slows down the Krebs cycle?
ATP and NADH (too much energy).
What is the rate-limiting step in the citric acid cycle?
Isocitrate dehydrogenase.
What is the main ATP-producing factory?
Mitochondria.
Where do the electron transport chain and oxidative phosphorylation happen?
The inner membrane of the mitochondria.
What is oxidation?
Giving up electrons.
E.g. H2 -> 2H + 2e-
What does phosphorylation mean?
Adition of a phosphate group to adenosine diphosphate.
What is oxidative phosphorylation?
The process of making ATP by donating electrons to complexes in the inner mitochondrial membrane.
