97 terms

A n P: metabolism

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Refers to all the chemical reactions that occur in the body
metabolism
There are two types of metabolism:
catabolism and anabolism
Chemical reactions that break down complex organic molecules into simpler ones; energy released...
catabolism
Give 3 area in which catabolic reactions occur:
glycolysis, the Krebs cycle, and the electron transport chain.
Chemical reactions that combine simple molecules and monomers to form the body's complex structural and functional components; energy used up...
anabolism
formation of peptide bonds between amino acids during protein synthesis, the building of fatty acids into phospholipids that form the plasma membrane bilayer, and the linkage of glucose monomers to form glycogen.
Anabolic reactions
Participate in energy exchanges in living cells; couples energy-releasing catabolic reactions to energy-requiring anabolic reactions
ATP (adenosine triphosphate)
can store chemical energy in its bonds and release it according to metabolic needs
ATP (adenosine triphosphate)
A-P-P-P
ATP (adenosine triphosphate) molecule = adenine and ribose and 3 phosphate groups
When complex molecules and polymers are split apart (catabolism), some of the energy is transferred to form " " and the rest is given off as heat.
ATP
When simple molecules and monomers are combined to form complex molecules (anabolism) , " " provides the energy for synthesis.
ATP
Simple molecules:
glucose, amino acid, glycerol, and fatty acids
complex molecules:
glycogen, proteins, and triglycerides
removal of electrons from an atom or molecule; the result is a decrease in the potential energy of the atom or molecule.
Oxidation
Give the 3 types of carbohydrates - saccharides
monosaccharides, disaccharides, and polysaccharides
Most biological oxidation reactions involve the loss of hydrogen atoms, this is called...
dehydrogenation
single sugar units; 3C - 6C; glucose, fructose, galactose, ribose, and deoxyribose
monosaccharides
compounds containing 2 MS; sucrose, lactose, and maltose
Disaccharides
How do Monosccharides, Disaccharide and Polysaccharides taste like?
MS and DS taste sweet, PS do not
complex carbohydrates; chains of MS units (mainly glc); starch, glycogen, and cellulose
polysaccharides
Starch:
storage polysaccharides produced by plants
Glycogen:
storage PS porduced by animals and humans
Cellulose:
storage PS produced by plants, indigestible by humans - dietary fiber
PS and DS must be digested but what happens to MS?
MS can be absorbed into the bloodstream and goes to the liver where it is converted to glucose (glc), body's main source of "Energy"
When body cells require immediate energy, how will they gain it?
glucose is oxidized to produce ATP. Glucose that are needed for immediated ATP production will enter several metabolic pathways.
Cells can use glucose to form several amino acids, which can be incorporated into proteins
Amino acid synthesis
Hepatocytes and muscle fibers perform glycogenesis, in which hundreds of glucose monomers are combined to form the polysaccharide glycogen.
Glycogen synthesis
What is the total storage capacity of glycogen in the liver and skeletal muscle?
125g in liver, and 375g in skeletal muscles
When the glycogen storage areas are filled up, hepatocytes transform the glucose to glycerol and fatty acids that can be used for lipogenesis, the synthesis of triglycerides, they are then deposited in adipose tissue's unlimited storage space.
Triglyceride synthesis
" " is an energy-balancing act between catabolic (decomposition) reactions, and anabolic (synthesis) reactions.
"Metabolism"
Before glucose can be used by body cells, where must it pass through first?
Glucose must first pass through the plasma membrane and enter the cytosol.
Glucose absorption in the gastrointestinal tract (and kidney tubules) is accomplished via " ".
"secondary active transport (Na -glucose symporters).
A high level of " " increases the rate of glucose diffusion into cells, except for neurons and hepatocytes.
"insulin"
oxidation relating to glucose:
breakdown of glucose to produce ATP = cellular respiration
3 process for cellular respiration:
glycolysis, the Krebs cycle, and the electron transport chain.
a set of reactions in which one glucose molecule is oxidized and two molecules of pyruvic acid are produced, which also produce two molecules of ATP and two energy containing NADH + H. This process is known as anaerobic cellular respiration because it does not require oxygen to produce ATP.
Glycolysis
A transition step that prepares pyruvic acid for entrance into the Krebs cycle. This step also produces energy-containing NADH + H plus CO2
Formation of acetyl coenzyme
Reactions that oxidize acetyl coenzyme A and produce CO2, ATP, energy-containing NADH + H, and FADH2. Requires oxygen to produce ATP and it is known as aerobic cellular respiration
Krebs cycle
Reactions that oxidize NADH + H and FADH2, and transfer their electrons through a series of electron carriers. Requires oxygen to produce ATP and it is known as aerobic cellular respiration
Electron transport chain
Certain amino acids can be converted in the " " to glucose.
"liver"
The process that glucose is formed from non-carbohydrate sources (glycerol, lactic acid, and amino acid) is called
gluconeogenesis
glucose is not converted back to glycogen but instead are newly formed
gluconeogenesis
What hormones stimulates gluconeogenesis?
cortisol (adrenal cortex) and glucagon (pancreas)
Which organ stimulate cortisol for gluconeogenesis?
adrenal cortex
Which organ stimulate glucagon for gluconeogenesis?
pancreas
" " converts glucose into glycogen; the " " breaks down glycogen into glucose.
"glycogenesis"..."glycogenolysis"
converts glucose into glycogen
glycogenesis
breaks down glycogen into glucose
glycogenolysis
the 10 reactions that convert glucose to pyruvic acid
glycolysis
Glut
glucose transporter
Glucose 1-phosphate is then converted to glucose 6-phosphate and finally to glucose
glycogenolysis
Why can't skeletal muscle cells cannot release glucose derived from glycogen into the blood stream?
Skeletal muscle lacks "phosphatase", the enzymes that converts glucose 6-phosphate into glucose.
In " ", glycogen is broken down into glucose 1-phosphate, which is then catabolized for ATP production via glycolysis and theKrebs cycle.
"skeletal muscle cells"
lactic acid produced by glycolysis in muscle cells can be converted to glucose in the " ".
"liver"
Large scale catabolism of fat and proteins occur during:
fasting, starving, low carb diet, and endocrince disorders
Nonpolar and are very hydrophobic molecules; do not dissolve in water
triglycerides (lipids)
how to transport triglycerides into watery blood?
Make them more water-soluble by combining them with proteins produced by the liver and intestine to form a lipoprotein. The inner core of the triglyceride will be surrounded by phospholipids, and cholesterol molecules.
which type of lipoprotein delivers cholesterol to body cells?
low-density lipids (LDL)
What do hepatocytes do with the broken-down saturated fats?
hepatocytes use some of the breakdown products to make cholesterol
contains 40-45% proteins, 5-10%, triglycerides, 30% phospholipids, and 20% cholesterol, remove excess cholesterol from body cells and the blood and transport it to the liver for elimination.
high-density lipoproteins (HDLs) aka good cholesterol
Why is HDL are known as good cholesterol?
It prevent accumulation of cholesterol in the blood. A high level of it will decrease coronary artery disease
Carry about 75% of the total cholesterol in blood and deliver it to cells throughout the body for use in repair of cell membranes, synthesis of steroid hormones and bile salts.
low-density lipoproteins (LDL) aka bad cholesterol
why is LDL are known as bad cholesterol?
It deposist cholesterol in and around smooth muscle fibers in arteries, forming a fatty plague increasing risk of coronary artery disease.
There are two sources of blood cholesterol:
diet (eggs, dairy, and meat), and the liver produces 80% of total cholesterol
Enzymes remove two carbon atoms at a time from the long chain of carbon atoms composing a fatty acid and attach the resulting two-carbon fragment to coenzyme A forming acetyl CoA. Then acetyl CoA enters Krebs cycle
beta oxidation (in fatty acid catabolism)
part of normal fatty acid catabolism; two acetyl CoA molecules form "acetoacetic acid"; some acetoacetic acids are converted into "beta-hydroxybutyric acid and acetone". These three substance are known as ...
ketone bodies
the formation of ketone bodies is called:
ketogenesis
increase production of ketone bodies
ketoacidosis example: diabetes mellitus
What is the % of stored triglycerides in adipose tissue?
98% of all body energy reserves
triglycerides must first be split into glycerol and fatty acids before it can be oxidize by muscle, liver and adipose. This process is called:
lipolysis
Lipolysis is catalyzed by which enzymes?
lipases.
which hormones enhance triglyceride breakdown into fatty acids and glycerol?
epinephrine and norepinephrine
what does liver, muscle, adipose tissue use fatty acids for?
ATP production
When are epinephrine and norepinephrine hormones release to breakdown triglyceride?
During sypathetic tone increases, such as during excercising.
other lipolytic hormones include:
cortisol (glucocorticoids hormones of the adrenal cortex), thyroid hormones, and insulinlike growth factors
Glycerol is converted by many cells of the body to " ", one of the compounds also formed during the catabolism of glucose.
"glyceraldehyde 3-phosphate"
When ATP supply in a cell is high, " " is converted into glucose, an example of glucogenesis.
"glyceraldehyde 3-phosphate"
If ATP is low, glyceraldehyde 3-phosphate enters the catabolic pathway to " ".
"pyruvic acid"
T or F: During catabolism, Fatty acids yield more ATP than glycerol?
True
During protein metabolism, what will happen to amino acids?
They are broken down to form ATP or used to synthesize new proteins for body growth and repair. Excess dietary amino acids are converted into glucose (gluconeogenesis) or triglycerides (lipogenesis) rather than being excreted in the urine or feces.
What hormones stimulates the activation of transportation of amino acids into body cells?
insulinlike growth factors (IGFs) and insulin.
After digestion, what is the fate of the proteins?
Many proteins function as enzymes; others are involved in transportation (hemoglobin) or serve as antibodies, clotting chemicals (fibrinogen), hormones (insulin), or contractile elements in muscle fibers (acting and myosin), and serves as structural comonents of the body (collagen, elastin, and keratin)
Proteins from worn out cells (red blood cells) are broken down into " ".
"amino acid". Some are converted into other AA, peptide bonds are re-formed, and new proteins are synthesized as part of the recycling process.
" " convert some amino acids to fatty acids, ketone bodies, or glucose
"hepatocytes"
Cells oxidize a small amount of amino acids to generate ATP via " " and the " ".
"Krebs cycle" and the "electron transport chain"
Before AA can be oxidized, what must happen to them first?
They must be converted into molecules that are part of the Krebs cycle, such as acetyl CoA, (removal of NH2)
The process of removal of NH2 from amino acid to enter the Krebs cycle is called...
deamination
deamination occurs in hepatocytes and produces what?
Produces the highly toxic ammonia (NH3). The hepatocytes then convert it to urea (harmless) that is excreted in the urine
The formation of peptide bonds between amino acids to produce new proteins
protein anabolism. Carried in ribosome of almost every cells in the body, directed by cells DNA and RNA.
All the hormones that stimulate protein synthesis:
insulinlike growth factors (IGFs), thyroid hormones (T3 and T4), insulin, estrogen, and testosterone
Adequate dietary protein needed during ....
growth, pregnancy, tissue repair, and body building
Out of 20 AA in the human body, how many are essentials?
10 essential amino acids. They must be in the diet because they cannot be synthesized by the body.
contains suffiecient amounts of all essential amino acids. Ex of food: beef, fish, poultry , eggs, and milk
complete protein
does not contain all essential amino acids. EX: leafy green veggies, legumes (beans and peas), and grains
incomplete protein
You measure energies in ...
calories and jules
measured under standard contitions (rest, fasting, quiet)
BMR (basal metabolic rate)
depends on activity and physio state
TMR (total metabolic rate)