SBI4U: Biochemistry

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isotonic
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when the concentrations of ECF (extracellular fluid) are the same as the ICF (intracellular fluid)
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hypotonic
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there is more water than solute in the environment
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hypertonic
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there is more solute than water in the environment
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ATP
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adenosine triphosphate
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carbohydrates, lipids, proteins, and nucleic acids
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4 compounds of life required by our cells in order to complete the functions of life
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oxidation
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loss of an electron: substance losing the electron is oxidized and called the reducing agent
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reduction
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gain of an electron- substance gaining the electron is reduced or called the oxidizing agent
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dehydration synthesis
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a reaction where a molecule of water is removed and small molecules are assembled into larger ones (requires energy)
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hydrolysis
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a reaction where a molecule of water is added, breaking macromolecules into micromolecules (produces energy)
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functional group
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a specific arrangement of atoms that take part in a chemical reaction (the reactive part). Everything else is considered ‘boring’ and is called an R group.
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hydroxyl
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have an OH group, general formula R-OH
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ketones
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double bonded O to two or more other carbons
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carboxyl
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carbonyl group and a hydroxyl group
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esters
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derivatives of carboxylic acids in which the OH of the carboxyl group is replaced by an OR from an alcohol (an O sandwiched between two carbons)
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amino
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organic compound with an amin- group (NH2)
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sulfhydryl
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sulfur bonded to a hydrogen, R-SH
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phosphate
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contains P, common to many biological compounds
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monomers
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small, similar molecular units
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polymers
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longs chains of monomers; can be a straight chain or branched
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carbohydrates
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an organic compound made up of sugar molecules; used as an energy source, can be stored within minutes for later use
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glycogen
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storage form in animals
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starch
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storage form in plants
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sugars
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contain C, H and O in a 1:2:1 ratio; most molecules in nature have a ring shape
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monosaccharides
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simple sugars containing just one sugar unit (e.g glucose, fructose, galactose, 3 isomers)
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disaccharides
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using a dehydration synthesis reaction, cells put together 2 monosaccharides to form this (e.g. sucrose, lactose, maltose)
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polysaccharides
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long polymer chains made up of simple sugar monomers (e.g. starch, glycogen, cellulose), held together by glycosidic bonds (alpha/beta)
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cellulose
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a building material in plants, protect cells; stiffens plant so it doesn’t fall over, made up glucose monomers, multiple chains form H bonds
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lipids
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non-polar, hydrophobic biological molecules
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functions of lipids
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store energy, form cell membranes, make hormones, insulate and protect organs
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fatty acids
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single hydrocarbon chain with a carboxyl functional group
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saturated triglycerides
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tend to be more solid, obtained from animals (e.g. butter and lard), difficult to break down, linked with single bonds
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unsaturated triglycerides
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liquid at room temperature, derived from plants (e.g. olive oil), easier to break down, linked with double bonds
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fats
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lipids made of two molecules (fatty acid, glycerol)
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phospholipids
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phosphate containing lipids; primary lipids of cell membranes. They have a hydrophilic head and a hydrophobic tail
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steroids
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large lipids (consist of four carbon rings) functional groups attached to the rings distinguish one from another
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cholesterol
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steroid that is an important component of the plasma membrane; diet rich in it can lead to atherosclerosis
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waxes
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large lipid molecules made of long fatty acid chains linked to alcohols or carbon rings
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proteins
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polymers that have many subunits a into three dimensional structures that determine its functions
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amino acids
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the building blocks of proteins
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peptide bonds
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link amino acids together via dehydration synthesis, creating polypeptides
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primary structure
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linear sequence of amino acids, changing one amino acid will change protein’s structure, therefore its function
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secondary structure
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hydrogen bonding causes them to spiral/coil, form either beta pleated sheets or an alpha helix, gives protein strength
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tertiary structure
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hydrophobic interactions causes protein to fold
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quaternary structure
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2 or more polypeptides come together forming complexed structures, create globular shapes
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denaturation
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(the breakdown of a polypeptide) can be caused by a change in temperature, change in pH, change in ionic concentration, exposure to chemical agents
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enzyme
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a protein that acts as a catalyst (speeds up the rate of the reaction without changing the products)
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enzyme inhibitor
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decrease enzyme activity
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competitive inhibitor
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similar to the enzyme substrate, enter the active site preventing the normal substrate from entering, therefore blocking normal binding
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non-competitive inhibitor
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attach to enzyme changing its shape therefore its function
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3 main parts of a nucleotide
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5 carbon sugar (deoxyribose or ribose), nitrogenous base, phosphate group
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purine
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double ring structure (adenine and guanine)
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pyrimidine
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single ring structure (thymine, uracil, cytosine)
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polynucleotide
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chain of nucleotides, curves to form a double helix

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