Molecular Biology Flashcards
Metabolism
sum of all chemical reactions that occur in the body
Catabolic Reactions
break down large chemicals and release energy
Anabolic Reactions
build up large chemicals and require energy
Ingestion
acquisition of food and other raw materials
Digestion
process of converting food into usable soluble form so that it can pass through membranes in the digestive tract and enter the body
Absorption
passage of nutrient molecules through the lining of the digestive tract into the body proper. absorbed molecules pass through cells lining the digestive tract by diffusion or active transport.
Respiration
consumption of oxygen into the body. cells use oxygen to convert glucose to ATP
Excretion
the removal of waste products produced during metabolic processes like respiration and assimilation.
Synthesis
creation of complex molecules from simple ones (anabolism)
Regulation
control of physiological activities
Homeostasis
maintain internal environment in a changing external environment with regulation of hormones and nervous system
Irritability
the ability to respond to a stimulus and is part of regulation
Growth
an increase in size caused by a synthesis of new materials
Photosynthesis
the process by which plants carbon dioxide and water into carbohydrates. sunlight is harnessed by chlorophyll to drive this reaction.
reproduction
generation of additional individuals of a species
Transport
the circulation of essential compounds required to nourish the tissues and the removal of waste products from the tissues
Assimilation
the building up of new tissues from digested food materials
Inorgranic compounds
compounds that do not contain carbon
Organic compounds
compounds made by living systems and contain carbon
Carbohydrates
composed of the elements carbon, hydrogen and oxygen in a 1:2:1 ration. used as storage forms of energy or as structural molecules. glucose and glycogen store energy in animals, whereas starch stores energy in plants.
Monosaccharide
single sugar subunits (glucose and fructose)
Disaccharide
two monosaccharide subunits joined by dehydration synthesis (maltose and sucrose)
Dehydration synthesis
loss of water molecule
Polysaccharide
polymers formed by removing water (glycogen and starch)
Polymers
chains of repeating monosaccharide subunits
Cellulose
polysaccharide that serves a structural role in plants, insoluble in water.
Hydrolysis
process of adding water to large polymers to break them down into smaller subunits
External Respiration
entrance of air into the lungs and the gas exchange between the alveoli and the blood
Internal Respiration
exchange of gas between the blood and the cells and the intracellular process of respiration
Dehydrognation
high-energy hydrogen atoms are removed from organic molecules. oxidation reaction.
Glycolysis
first stage of glucose catabolism. series of reactions that leads to the oxidative breakdown of glucose into 2 molecules of pyruvate, production of ATP, reduction of NAD+ into NADH. occurs in cytoplasm.
Glycolysis net reaction
Glucose + 2 ADP + 2 Pi + 2NAD+ ——–> 2 Pyruvate + 2ATP + 2NADH + 2H+ + 2H2O
Substrate Level Phosporylation
ATP synthesis is directly coupled with the degradation of glucose without the participation of an intermediate molecule. degradation of one glucose yields net of 2 ATP from glycolysis and one ATP for each turn of the Kreb’s Cycle (four in total)
Fermentation
anaerobic conditions of glycolysis producing ethanol or lactic acid
Alcohol Fermenation
only occurs in yeast and some bacteria. pyruvate is converted to ethanol.
Lactic Acid Fermentation
occurs in certain fungi, bacteria, and in human muscles cells during strenuous activity. when oxygen supply to muscle cells lags behind the rate of glucose catabolism
Cellular Respiration
most efficient catabolic pathway used by organisms to harvest the energy stored in glucose. yields 36-38 ATP. aerobic process and occurs in eukaryotic mitochondrion. 3 stages.
Pyruvate Decarboxylation
during cellular respiration the pyruvate is transported from the cytoplasm into the mitochondrial matrix where it loses a CO2, and the acetyl group that remains is transferred to coenzyme A to form acetyl-CoA.
Citric Acid Cycle/Kreb’s Cycle
chemical reaction used by all aerobic organisms to produce energy.
Kreb’s Cycle Net Reaction
2 acetyl-CoA + 6NADH+ + 2FAD + 2GDP+ 2Pi + 4H2O —–> 4CO2 + 6NADH + 2FADH2 + 2GTP + 2H+ + 2CoA
Electron Transport Chain
complex carrier mechanism located on the inside of the inner mitochondrial membrane.
Cytochromes
electron carriers that resemble hemoglobin in the structure of their active site. functional unit contains a central iron atom that is capable of reducing or oxidizing
Oxidative Phosporylation
process that accounts for 90% of ATP used by body
Other Energy Sources
when glucose supplies run low body uses other carbohydrates, fats, and proteins
Carbohydrates (Alt Energy)
disaccharides are hydrolyzed into monosaccharides - these can be converted into glucose or glycolytic intermediates. glycogen stored in the liver can be converted into a glycolytic intermediate
Fats (Alt Energy)
triglycerides stored in adipose tissue are hydrolyzed by lipases to fatty acids and glycerol. fats yield the greatest number of ATP per gram
Proteins (Alt Energy)
last macromolecule to degrade for energy when carbs or fat not available.
Transamination Reactoin
amino acid loses amino group to form an a-keto acid
Oxidative Deamination
removes one ammonia molecule directly from amino acid. this ammonia excreted by vertebrates
Enzymes
organic catalysts that affect the rate of chemical reaction without being changed. regulate metabolism by speeding and slowing down reactions. they do not alter equilibrium constant. pH and temperature sensitive. protein or conjugated protein based.
Coenzyme
nonprotein component of enzyme that must be present for enzyme to function. not all enzymes have a coenzyme.
Substrate
molecule upon which an enzyme acts
Active Site
area on each enzyme to which the substrate binds
Enzyme-Catalyzed Reactions
most are reversible - product can be decomposed
Lock & Key Theory
spatial structure of an enzyme’s active site is exactly complementary to spatial structure of substrate. theory is now largely discounted.
Induced Fit Theory
active site of enzyme has flexibility to accept substrate.
Enzyme Specificity
enzyme action and reaction rate depend on several environmental factors (temperature, pH and concentration). optimal temp is around 40C, optimal pH is around 7.2 for most enzymes
Competitive Inhibition
possible for molecules similar to substrate to bind to active site. substrate can overtake competitor, but it requires much higher concentration of substrate than usual.
Noncompetitive Inhibition
substance that forms strong covalent bond with enzyme and prevents it from binding with substrate. irreversible
Allosteric Inhibition
noncompetitive inhibitor binds anywhere but the active site thus changing the structure of the enzyme and the active site.
Hydrolysis
digest large molecules into smaller components (lactase, protease, lipase)
Lactase
hydrolyzes lactose to the monosaccharides glucose and galactose
Protease
degrade proteins to amino acids
Lipases
break down lipids to fatty acids and glycerol
Synthesis
can be catalyzed by same enzymes as hydrolysis reactions, but reactions are reversed. required for growth, repair, regulation, protection, production.
Prosthetic Groups
cofactors that bind to the enzyme by strong covalent bonds.
