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What is dehydration reaction?
Connects monomers, also known as condensation reaction. When two molecules are covalently bonded to each other through loss of water molecules.
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What is hydrolysis?
- The reverse of dehydration. Disconnects polymers. Bonds between the monomers are broken by the addition of water molecules.
- ex: the process of digestion.
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Dehydration and hydrolysis reactions are essentially the reverse of each other, and are facilitated by .
enzymes
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What are monosaccharides?
- * molecular formulas are some multiple ot ous.
- *names for sugara ene in -ous.
- *Have a carbonyl group and multiple hydroxyl groups
- *Are a major fuel for celluar work
- *functions as the raw material for the synthesis of other monomers, including those of amino acids and fatty acids.
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What is disaccharide?
- consist of two monosaccharide joined by a glycosidic linkage, a convalent bond formed between two monosccharides by dehydration reaction.
- ex: maltose is formed by the linkage of two molecules of glucose
- sucrose-table sugar- glucose and fructose
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What are polysaccharides?
- *Polymers of hundreds to thousands of monosaccharides joined by glycosidic linkages.
- *An energy storage macromolecules that is hydrolyzed as needed
- ex: for fuel storage: Glycogen ( animals only) & Starch (plants only)
- For Structure: Cellulose ( plants only, cell wall)
- *Strands form hydrogen bonds with other strands
- *groups of polymers form strong strands, microfribrils that are basic building material for plants and humans
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Components of a fat molecule
- *contains glycerol and fatty acids
- *three fatty acids are joined to glycerol by ester linkage, creating a triacylglycerol
- *fats separate themselves from water
- *major function is energy storage
- *c-shion vital organs and insulation
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What is glycerol?
a three carbon skeleton with a hydroxyl group attached to each
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What are fatty acids?
a carboxyl group attached to a long carbon skeleton, often 16 to 18 carbons long (very hydrophobic)
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What are saturated fats?
- * most animal fats
- *solid at room temperature
- *contribute to cardiovascular disease through plaque deposits
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What are unsaturated fats?
- *plant and fish fats, known oils
- *liquid at room temperature
- *the kinks provided by the double bonds pervent the molecules from packing tightly together
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What are trans-fats?
a type of unsaturated fat that occurs at low levels in dairy and meat products
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What are phospholipids?
- = a fat with two fatty acids attached to glycerol plus phospholipids group at the third positions
- *major components of cell membrane
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The 4 components of an amino acid.
- consist of four components attached to a central carbon:
- 1.alpha carbon
- 2. a hydrogen atom
- 3. a variable R group ( or side chain)
- 4.a carboxyl group
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A polar R group.
there hydrophilic
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A non-polar R group.
there hydrophobic
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What are acidic amino acids?
are those with side chains that are generally negative in charge owing to the presence of a carboxyl group
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What are basic amino acids?
have amino groups in their side chains that are generally positve in charge
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What is the primary structure?
- * is the first level of protein structure
- *is its unique sequence of amino acids
- *is found in the blood that transport vitamin A and one thyroid hormones throughout the body
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What is the secondary structure?
- * second level of protein structure
- *hydorgen bonds at regular intervals along the polypeptide backbone
- *coils an alpha helix
- *folds beta pleated sheets
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What is the tertiary structure?
- *thrid level of protein structure
- *determine by interactionsbetween R groups and polypeptide backbone
- *hydrophobic interaction contributes to the tertiary structure
- *consist of hydrogen bonds, ionic bond and van der Waals
- *Disulfide bridges- reinforce the shape of the protein by the covalent bond
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What is the Quaternanry sturcture?
- *the fourth level of the protein structure
- *results from the aggregation of two or more polypeptide subunits
- ex: collagen-fibrous protein of three polypeptides that are supercoiled like a rope
- hemoglobin-a globular protein with two copies of two kinds of polypeptides
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What are chaperone proteins?
- *protein molecules that assist in the proper folding of other proteins
- *keep the new polypeptide segregated from "bad influences" in the cytoplasmic enviroment while it folds spontaneously
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What is a gene?
- *the amino acid sequence of a polypeptide is programmed by a unit of inheritance
- *consist of DNA
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What is DNA (deoxyribonucleic acid)?
- *enables living organisms to reproduce their complex components from one generation to the next
- *provides directions for its own replication
- *directs RNA synthesis and, through RNA, controls protein synthesis
- *genetic material that organisms get from their parents
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What is RNA (ribonucleic acid)?
- *enable living organisms to reproduce their complex components from one generations to the next
- *interacts with the cell's protein-synthesizing machinery to direct production of a polypeptide, which folds into all or part of a protein
- *conveys genetic instructions for building proteins form the nucleus tot he cytoplasm
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What is phosphodiester?
- *connects polynucleotides
- *the linkage between the 3' carbon atom and the 5' carbon if tge pentose sugar
- *consists of a group of strong covalent bonds
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What are the three components of nucleic acids?
- 1.nitorgenous base
- 2. a five-carbon sugar (pentose sugar)
- 3. phosphate group
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What are the base pairing rules?
- *an RNA molecule is single polyncleotide chain
- *DNA molecule have two polynucletide strands that spiral around an imginary axis to form a double helix
- *Adenine (A) pairs with Thymine (T)
- *Guanine (G) pairs with Cytosine (C)
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What are eukaryotic cells?
- *has a plasma membrane
- *a cytosol within the cell
- *consist of chromosomes
- *ribosomes-organells that make proteins
- *chromosomes are in the nucleous
- *has many organelles, membrane bound
- *size is 10-100 times larger
- *domain is eukarya
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What are prokaryotic cells?
- *plasma membrane
- *a cytosol within the cell
- *chromosomes
- *ribosomes
- *has nucleoid-not membrane enclosed
- *no organelles
- *size is small
- *domain is archaea & bacteria
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What is smooth ER (endoplasmic reticulum)?
- *outer surface lacks ribosomes
- *process includes synthesis of lipids, metabolism of carbohydrates, and detoxification of drugs and poisons
- *enzymes are improtant in the synthesis of lipids, including oils, phospholipids, and steroids
- *detoxify drugs and poisons especially in liver cells
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What is rough ER?
- *ribosomes attached to the outside
- *packages proteins into transport vesicles
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What is the Fluid Mosaic Model?
- *Hydrophilic regions of proteins and phospholipids are in maximum contact with water
- *Hydorphobic regions are in a nonaqueous enviroment
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What factors affect membrane fluidity?
- 1. Temperature: fluidity decreases as temperature decreases due to tighter packingof phospholipids
- 2. Membrane constituents: unsturated fatty acids make membranes more fluid because the kinks prevent tight packing
- 3. Cholesterol-restrains the movement of phospholipids ans reduces fluidity
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What are peripheral proteins?
loosely bounded to the surface of the membrane, interacting with other proteins
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What are integral proteins?
penetrate the hydrophobic core of the lipid bilayer, often completely spanning the membrane (a transmembrane protein)
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Where are membranes synthesized?
- *membranes are asymmetrical, having distinctive inside and outside faces
- *lipid layers may differ in specific lipid composition
- *proteins are directional
- *carbohydrates are only on the other surface
- *membranes are manufactured in ER
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What are passive transpot?
- 1. Diffusion-passive movement of molecules down a concentration gradient
- 2. Facilitated diffusion-the passive movement of molecules down its concentration gradient via a transport protein
- *Osmosis is the passive transport of water
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What is active transport?
- *the active tansport of molecules against a concentration gradient
- *requires metabolic energy
- *is the pumping of solutes against thein gradients
- *critical for a cell to maintain its internal concentration of small molecules
- *performed by specific proteins embedded in the membranes
- *ATP supplies tghe energy for most active transport
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What is facilitated diffusion?
- *requires transport proteins, which
- -have specific binding sites for the solute
- -become saturated when translocating passengers at full capacity
- -can be inhibited by molecules similar to normal "substrate."
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What is osmosis?
- *is the diffusion of water across a selectively permeable membrane
- *water molecules move from less concentrated (hypotonic) to more concentrated
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What is hypertonic?
- *the cell will lose water to its enviroment, shrivel and probably die
- *an increase in the salinity of a lake can kill animals there; if the lake water becomes hypertonic to the animales' cells, the cells might shrival and die
- *taking up too much water can be just as hazardous to an animal cell as losing water
- *water will enter the cell faster than it leaves, and the cell will swell and lyse (burst) like an overfilled water balloon
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What is cotransport?
- a single ATP-powered pump that transports one solute can indirectly drive the active transport of several other solutes in a mechanism
- ex: plants use the gradient of hydrogen ions that is generated by proton pumps to drive the active transport of amino acids, sugars, and other nutrients into the cell
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What is endocytosis?
- *macromolecules and particulate matter enter the cell by forming new vesicies from the plasma membrane.
- *reverse of exocytosis
- *Three types:
- 1. phagocytosis-celluar eating
- 2. pinocytosis-celluar drinking
- 3. receptor-mediated endocytosis
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What is phagocytosis?
the cell engulfs a particle by extending pseudopodia and packaging it in a large vacuole, then digesting it when the vacuole fuses with a lysosome
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What is pinocytosis?
- *a cell creates a vesicle around a droplet of extracellular fluid
- *a non-specific process
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What is receptor-mediated endocytosis (RME)?
- *very specific in what substances are being transported
- *triggered by receptor-ligand interaction (which triggers the formation of a vesicle
- *enables a cell to "store up" componds
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What is exocytosis?
a transport vesicle budded from the Golgi apparatus is move by the cytoskeleton to the plasma membrane
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What are anabolic pathways?
- *in contrast, consume energy to build complicated molecules from simpler ones; they are sometimes called biosynthetic pathways
- ex: the synthesis of a protein from amino acids
- * used to drive uphill reactions
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What are catabolic pathways?
- *breakdown pathways
- *energy is released form the downhill reactions
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What are endergonic reactions?
- *is one that absorbs free energy from its surroundings
- *stores free energy in molecules
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What are exergonic reactions?
- *proceeds with a net release of free energy
- *since chemical mixture loses free energy, change in G is negative
- *occur spontaneously
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What is free energy?
- *is the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell
- *can be calculated by change in G=change in H-Tchange inS
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What is the first law of thermodynamic?
- *the energy of the universe is constant
- *energy can be transferred and tansfromed but it cannot be created or destroyed
- *also known as the principle of conservation of energy
- ex: energy in the food will be conerted to the kinetic energy of the cheetah's movement
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What is the second law of thermodynamic?
- *every energy transfer or transformation increases the entropy of the universe
- *there is an unstoppable trend toward randomization of the universie verse as a whole
- ex: disorder is added to the cheetah's surroundings in the form of heat and the small molecules that are the by-products of metabolism
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The break down of glucose to CO2 and water=-687kcal/mol.
- C6H12O6+6O2>6CO2+6H2O
- *converts sugar and oxygen to carbon dioxide and water
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The reverse break down of glucose =+686kcal/mol
- 6CO2 +6H2O>C6H12O6+6O2
- *must be strongly endergonic
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What are the parts of an ATP molecule?
- *base (adenine)
- *three phosphates
- *a sugar (ribose)
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How does enzymes lower EA but not change in G?
- *An enzyme catalyzes a reaction by lowering the EA barrier, enabling the reactant molecules to absorb enough energy to reach the transition state even at moderate temperatures.
- *cannot change change in G for a reaction; it cannot make an endergonic reaction exergonic
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What are factors that affect enzyme activity?
- 1. Substrate concentration
- 2. Temperature
- 3.pH
- 4.Cofactors
- 5. Inhibitors
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What is substrate concentration?
- *increase in substrate concenteration=increase in rate
- *there is a limit to how fast a reaction can occur
- *a high substrate concentrations, the active sites on all enzymes are engaged, called enzyme saturation
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How temperature effect enzymes?
- *increase in temperature=increase in rate
- *at some point heat denatures protein
- *each enzyme has as optimal temperature
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How pH effect enzyme?
- *influences shapt of therefore reaction rate
- *each enzyme has an optimal pH
- *this falls between pH6-8 for most enzymes
- *exceptions include digestive enzymes in the stomach
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How does cofactors effect enzyme?
- *no-protein helper for enzyme activity
- *includes inorganic molecules
- *organic cofactors, coenzymes, include vitamins or molecules derived from vitamins
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How does inhibitor effect enzymes?
- *covalent interactions or ionic with enzymes
- *competitive inhibitor binds to the same site as the substrate, and blocks substrate binding
- *noncompetitive inhibitor binds somewhere other than the active site, ans block substrate binding via altering shape of enzyme
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What is feedback inhibition?
is a metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway
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