Metabolism Flashcards
Difference between glucose and glycogen?
glucose - sugar in blood stream, glycogen - store glucose
Glucose is the sugar in our bloodstream that our body uses for energy. Glycogen is a stored form of energy. After eating, when there is too much glucose to be used, the extra glucose is converted to glycogen to be stored.
How does glucose become glycogen?
Glycogenesis
Glycogenesis is the formation of glycogen from glucose. Glycogen is synthesized depending on the demand for glucose and ATP (energy). If both are present in relatively high amounts, then the excess of insulin promotes the glucose conversion into glycogen for storage in liver and muscle cells.
What happens to glycogen if not used?
When the level begins to decline—either because you have not eaten or are burning glucose during exercise—insulin levels will also drop. When this happens, an enzyme called glycogen phosphorylase starts breaking glycogen down to supply the body with glucose.
Where is glycogen stored?
The two major sites of glycogen storage are the liver and skeletal muscle. The concentration of glycogen is higher in the liver than in muscle (10% versus 2% by weight), but more glycogen is stored in skeletal muscle overall because of its much greater mass.
Where does glycose come from?
Glucose or sugar comes from the food we eat. Carbohydrates such as fruit, bread pasta and cereals are common sources of glucose. These foods are broken down into sugar in our stomachs, and then absorbed into the bloodstream
how does insulin work on glucose
Insulin helps your body turn blood sugar (glucose) into energy. It also helps your body store it in your muscles, fat cells, and liver to use later, when your body needs it. After you eat, your blood sugar (glucose) rises. This rise in glucose triggers your pancreas to release insulin into the bloodstream.
How store lipids in body?
triglycerides - TAG
Lipolysis?
TAG- > glycerol + FA
Lipogenesis?
glycerol +FA -> TAG
Beta oxidation?
Fatty acids to Acetyl-Coa
Kreb cycle?
glucose and other molecules are broken down in the presence of oxygen into carbon dioxide and water to release chemical energy in the form of ATP.
If eating too much sugar and can’t use -
Lipogenesis
If breaking down Fats for energy?
Lipolysis (Glycerol + Fatty Acids) -
Glycerol -> DHAP
FA -> Acetylcoa (16c -> 8 x 2 c)
3 pathways (4) of gluconeogenesis?
AA, Lactic Acid, glycerol + Odd chain FA (17 on the chain so one space 3c to use)
Why do we need pentose phosphate pathway?
The pentose phosphate pathway is primarily catabolic and serves as an alternative glucose oxidizing pathway for the generation of NADPH that is required for reductive biosynthetic reactions such as those of cholesterol biosynthesis, bile acid synthesis, steroid hormone biosynthesis, and fatty acid synthesis.
glycolysis vs gluconeogenesis?
glycolysis makes ATP . Gluconeogenesis makes glucose
what do ribosomes do?
make proteins
endothelial cells?
The endothelium is a thin layer of single flat (squamous) cells that line the interior surface of blood vessels and lymphatic vessels. Endothelium is of mesodermal origin. Both blood and lymphatic capillaries are composed of a single layer of endothelial cells called a monolayer.
ependymal cells ?
are simple cuboidal cells that line the ventricles in the brain and the central canal in the spinal cord.
trophic center ?
Any part of the central nervous system whose proper functioning is thought to be necessary for the nutrition, growth, or maintenance of a peripheral part of the body; such as, the parietal lobe for the development of the muscles of an extremity.
What affects membrane capacitance?
The membrane capacitance is proportional to the cell surface area and, together with the membrane resistance, determines the membrane time constant which dictates how fast the cell membrane potential responds to the flow of ion channel currents.
Guillain-Barre syndrome
is a rare disorder in which your body’s immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms. These sensations can quickly spread, eventually paralyzing your whole body.
peroximsomes - refsum disease, Zellweger, adrenoleukodystrophy
synthesize cholesterol, bile acids and plasmalogenes (important membrane phosopholipid - esp white brain matter)
A major function of the peroxisome is the breakdown of very long chain fatty acids through beta oxidation. In animal cells, the long fatty acids are converted to medium chain fatty acids, which are subsequently shuttled to mitochondria where they eventually are broken down to carbon dioxide and water.
peroxisome vs lysosome?
They differ from lysosomes in the type of enzyme they hold. Peroxisomes hold on to enzymes that require oxygen (oxidative enzymes). Lysosomes have enzymes that work in oxygen-poor areas and lower pH. Peroxisomes absorb nutrients that the cell has acquired.