1.5 Nucleic Acids & 1.6 Enzymes_Completed PDF

1.5 – Macromolecules: Nucleic Acids 4. NUCLEIC ACIDS ADeoxyribonucleicacid Functions: Hereditary material as DNA, and various roles including protein synthesis as RNA. Ribonuc...

1.5 – Macromolecules: Nucleic Acids 4. NUCLEIC ACIDS ADeoxyribonucleicacid Functions: Hereditary material as DNA, and various roles including protein synthesis as RNA. Ribonucleic acid Structure: o a chain of __________________________________________________________________ nucleotidemonomersjoined by ___________. phosphof ribose o The nucleotide is made up of three parts; the sugar ring, a phosphate functional group, and a nitrogenous base: adeninecytosine gfin.tn hymine 8 0 0 until RNA 3 n bisebackbone Phosphodiester I bond antiparallel 5 20  o DNA is a __________________, where the two strands run ________________, double helix antiparallel between and the ____________________________________________________ base pairs are connectedby Hbonds complimentary base pairs. Complimentary base pairs are ____________________ and C G o RNA is typically single stranded. of purines GA Pyrmidines et PUGA Cytosine Cytosine Nucleobases Guanine Guanine Base pair Adenine Adenine Uracil Thymine helix of sugar-phosphates Nucleobases Nucleobases of RNA of DNA RNA DNA Ribonucleic acid Deoxyribonucleic acid NUCLEIC ACID PRACTICE QUESTIONS 1. Describe two differences and two similarities between RNA and DNA. Both made of nucleotides Both carry genetic information DNAhas the basethymineRNAhas uracil 21 2. Sketch a nucleic acid and identify the functional groups. 3. Write the complimentary base pairs for the DNA sequence: 5’CCGCAAACCCGCTATGTT3’ 4. What does the 3’ and 5’ mean and in what direction is a DNA strand built? 22  1.6 – Enzymes Enzymes are… speedup reactions proteins that catalyze Most enzymes are named after the reaction they catalyze and their names end in “ase”. Ex. Lactase hydrolyze lactose Amylase amylosehydrolysis Enzyme Structure The _________________ fits precisely in the ___________________ active site in order r the reaction to substrate proceed. All enzymes are highly specific to only ____________ substrate. one substrate Is notused up in rxn recyclable Induced-fit model: the substrate interacts with the functional groups within the e enzyme’s active site. This helps weaken the bonds in the substrate and increase the rate of reaction. conformationalchange Enzymes and Biological Reactions: The interactions within the enzyme- substrate complex allow bonds to be weakened and easily broken, lowering the activation energy for the reaction. Enzymes lower activation energy by: 1. me interrere time I s is a coz420 Haco 2.Transfer ofelectrons to orfromsubstrate 3.TransferHt ionsto orfromsubstrate 23 All enzymes function in an optimal environment. Any changes to those conditions can alter the rate of the reaction. 1. Temperature 2. pH 3. Enzyme concentration 4. Substrate concentration Environmental Graphic Data Description Factor Temperature limited activity at cold temp peakactivity a bodytemp zeroactivity at veryhot temp proteinsdenatured pH most enzymeshave a peak D some enzymespeak pH2 if in the stomach Enzyme 2 in 12 zero enzyme zero activity concentration veryquicklypeak butthen plateaus substrate try L 9397m addingmoredoesn'tchange enzymatic Substrate t it 3 6 concentration substrate energy activity eventually will taper off as enzymebecomeslimiting 24 Enzyme activity can also be regulated by a variety of other factors: 1. cofactors coenzymes 2. 3. 4. 5. 1. Cofactors/Coenzymes activators Turn on enzymes that are otherwise off conformationalchange activates 2. Competitive Inhibitors 3. Non-Competitive Inhibitors active site binds to must be similar in structure usually on turned off by the somewhereotherthanactive inhibitor Gifts changesshape ofactivesite 25 4. Allosteric Changes Allosteric change: turned on When an activator binds: it stabilizes the enzyme in its active form encouragessubstratebinding When an inhibitor binds: am 5. Feedback Inhibition The product of one reaction becomes the substrate of another enzymatic reaction. Each enzyme is highly specific to the new product in the pathway. The product formed in the last step of the pathway can become an inhibitor. NegativeFeeback loop Endproduct inhibitor inhighconcentrations Enzymes Practice Questions pg. 42 #3, 7, 9, 12 26