BIOL 117 Week 2 Vocabulary + Concepts

Content 3.14-3.16

glycolysis

cytosolic reactions that break down glucose into pyruvate and lactate, H+, NADH, water, and ATP
yields 2 pyruvate + 2 ATP + 2 NADH + 2 H+ + 2 H2O

substrate-level phosphorylation

ATP forms by this process in which a phosphate group is transferred from a phosphorylated metabolic intermediate directly to ADP

krebs cycle (citric acid or tricarboxylic acid cycle)

mitochondrial pathway that utilizes breakdown products of organic macromolecules to yield CO2, ATP, and H+
one rotation produces 2 CO2 and 4 pairs of H atoms are transferred to coenzymes
yields 2 CO2 + CoA + 3 NADH + 3 H+ + FADH2 + GTP

acetyl coenzyme A

derived partly from all three types of nutrient macromolecules; the major substrate entering the krebs cycle

oxidative phosphorylation

process occurring on inner mitochondrial membranes in which ATP is formed from ADP and Pi, using energy released when O2 combines with H+ to form water

yields H2O + NAD+ + 3 ATP

electron-transport chain

regenerates hydrogen-free forms of the coenzymes NAD+ and FAD by transferring the H+ to O2; reactions of the electron-transport chain produce a H+ gradient across the inner mitochondrial membrane. the flow of H+ back across the membrane provides energy for ATP synthesis.

chemiosmosis (oxidative phosphorylation)

H ions flow back to the matrix side

ATP synthase

enzyme embedded in the inner mitochondrial membrane, forms a channel in the inner mitochondrial membrane allowing for a process known as chemiosmosis

catabolism of carbohydrates

max. of 38 molecules of ATP can form from catabolism of 1 molecule of glucose up to 34 from oxidative phosphorylation, 2 from glycolysis, and 2 from the Krebs cycle

carbohydrates

stored as glycogen in liver and skeletal muscles

glycogenesis

enzymatic process in which glucose is derived from glycogen

glucogenesis

enzymatic process in which glucose is synthesized from breakdown products of some amino acid, lactate, and glycerol (noncarbohydrate precurors)
major substrate is pyruvate formed from lactate

triglycerides

stored in adipose tissue; provide about 80% of stored energy in the body

fatty acid (FA) catabolism and synthesis

fatty acid broken down in mitochondrial matrix by beta oxidation to form acetyl coenzyme A and H+, which combines coenzymes

protein catabolism

protein broken down to free amino acids by proteases

keto acids

formed by removal of amino groups from amino acids; can be ither catabolized via the krebs cycle to provide energy for the synthesis of ATP or used in the synthesis of glucose and fatty acids

transamination

transfer of the amino group from an amino acid to a keto acid

adipocytes

most of the body’s fat stored in these specialized cells

adipose tissue

clusters of adipocytes

beta oxidation

splits off a molecule of acetyl coenzyme A from the end of the fatty acid and transfers two pairs of hydrogen atoms to coenzymes (one pair to FAD, the other to NAD+)

glycerol 3-phosphate

phosphorylated form of glycerol

proteases

a few enzymes required by protein catabolism to break the peptide bonds between amino acids (proteolysis)

oxidative deamination

the amino group gives rise to a molecule of ammonia (NH3) and is replaced by an oxygen atom derived from water to form "a “keto acid”

essential amino acids

9 amino acids corresponding to keto acids from the food we eat

“negative nitrogen balance”

refer to a net loss of amino acids in the body over any period of time

“positive nitrogen balance”

refer to a net gain of amino acids in the body over any period of time

essential nutrients

necessary for health but cannot be synthesized in adequate amounts by the body and most therefore be provided in the diet

water-soluble vitamins

B vitamins and vitamin C; excreted in urine

fat-soluble vitamins

vitamins A, D, E, and K; ingestion of high amounts leads to accumulation in adipose tissue and may produce toxic effects

vitamins

group of 14 organic essential nutrients required in very small amounts in the diet