1/21/15 1 Welcome to Introductory Biology: Cell and Developmental Biology BIOMG 1350 Tony Bretscher Ken Kemphues Instructors1/21/15 2 Lecture slides will be posted on Blackboard by 6:00pm on the day before the lecture. They do NOT contain everything you need to know – selected key items are removed to keep you entertained and engaged in the lecture. Print a copy and bring it to class to take notes on. Lectures (2 credits) Mondays and Wednesdays 9:05– 9:55am Call Auditorium 1/18/13%1%Figure 7-5 Essential Cell Biology Most%RNAs%are%single0stranded%and%%can%fold%into%specific%structures%using%base%pairing%Type%of%RNA% Size% Func6on%mRNA%(messenger%RNA)% 100%–%10%kb% Protein%coding%rRNAs%(ribosomal%RNA)% 120%G%4,800% Protein%synthesis%(machinery)%tRNAs%(transfer%RNA)% 73%G%93% Protein%synthesis%(adaptors%to%mRNA)%snRNA%(small%nuclear%RNA)% Short% mRNA%processing%snoRNAs%(small%nucleolar%RNA)% Short% rRNA%processing%miRNA%(micro%RNAs)% 22% Gene%regula6on:%block%mRNA%transla6on%siRNA%(small%interfering%RNAs)% 22% Gene%regula6on:%degrade%mRNAs%telomerase%RNA% ~400% Telomeric%DNA%synthesis%Several%types%of%RNA%are%produced%in%cells%and%there%are%a%number%of%other%classes%of%RNAs%%Lecture%3%Summary%%• %%Cells%are%made%up%of%about%70%%water,%4%%other%small%molecules,%15%%protein,%6%%RNA,%and%polysaccharides,%phospholipids%and%DNA%together%making%up%about%5%.%%• %%The%four%elements%–%H,%C,%N%and%O%–%make%up%about%99%%of%the%cell.%Na,%Mg,%P,%S,%Cl,%K%and%Ca%are%all%important%and%make%up%most%of%the%rest.%• %The%major%macromolecules%of%the%cell,%polysaccharides,%proteins%and%nucleic%acids,%are%all%constructed%from%smaller%subunits.%• %Carbohydrate%(CH20)n%polymers%are%made%up%by%covalent%bonds%between%adjacent%sugar%subunits%with%the%elimina6on%of%H20.%• %Carbohydrates%exist%in%cells%as%monosaccharides,%disaccharides%and%polysaccharides.%They%are%important%for%energy%storage%(glycogen),%structural%support%(plant%cell%walls),%and%protein%and%lipid%modifica6on.%• %The%nucleic%acids%ribonucleic%acid%(RNA)%and%deoxyribonucleic%acid%(DNA)%are%assembled%from%nucleo6des.%• %Nucleo6des%consist%of%a%NGcontaining%base%linked%to%the%1’%posi6on%of%a%sugar%(ribose%for%RNA%and%deoxyribose%for%DNA),%and%one%or%more%phosphates%linked%to%the%5’%posi6on.%• %Bases%are%either%pyrimidines%with%a%single%ring%(cytosine%or%thymine%in%DNA,%cytosine%and%uracil%in%RNA)%and%purines%with%a%double%ring%(adenine%and%guanine%in%both%DNA%and%RNA).%• %Nucleo6des%are%joined%together%by%a%phosphodiester%linkage%through%the%5’G%phosphate%to%the%3’%hydroxyl.%• %%DNA%and%RNA%chains%always%have%a%5’%end%(with%a%phosphate)%and%a%3’%end%(with%a%free%OH).%• %%The%informa6on%contained%in%DNA%is%encoded%by%the%sequence%of%its%bases,%AGCT%• %%In%double%stranded%DNA,%the%two%chains%run%in%opposite%direc6ons,%5’G3’%and%3’G5’.%• %%In%double%stranded%DNA,%A%always%pairs%with%T%through%two%HGbonds,%and%C%with%G%through%3%hydrogen%bonds.%• %This%complementary%baseGpairing%allows%DNA%to%act%as%its%own%template%during%semiGconserva6ve%DNA%replica6on.%• %%The%DNA%in%chromosomes%is%very%long%and%highly%compacted.%• %%RNA%is%chemically%similar%to%DNA,%except%that%it%uses%ribose%in%place%of%deoxyribose%and%uracil%in%place%of%thymine.%• %%Specific%regions%of%the%DNA%sequence%–%called%genes%–%are%used%as%a%template%for%the%synthesis%of%a%complementary%RNA%sequence%by%the%protein%RNA%polymerase.%This%process%is%known%as%transcrip6on.%This%process%transfers%the%gene6c%informa6on%into%an%RNA%sequence:%this%RNA%is%called%messenger%RNA,%or%just%mRNA.%• %mRNA%is%translated%into%a%specific%amino%acid%sequence%to%generate%a%protein.%• %This%informa6on%transfer%of%DNA%G>%RNA%G>%Protein%is%known%as%the%‘central%dogma’.%• %The%human%genome%has%been%sequenced,%and%it%encodes%about%21,000%genes.%• %Hereditary%(‘gene6c’)%diseases%can%result%from%a%muta6on%(altera6on%in%DNA%sequence)%in%a%specific%gene%that%is%then%transcribed%into%RNA%and%can%give%rise%to%a%protein%with%a%defec6ve%amino%acid%sequence.%• %RNA%can%fold%up%into%many%different%3Gdimensional%structures%through%baseGpairing%within%a%single%chain.%• %The%are%many%different%types%of%RNA%in%the%cell.%In%addi6on%to%mRNA,%rRNA%is%a%cri6cal%component%of%ribosomes%and%tRNAs%are%involved%in%protein%synthesis%(topics%of%next%lecture),%as%well%as%several%types%of%regulatory%RNAs,%and%other%types.%The handouts on the Web will include a summary of the important points from the lecture Lecture Slides are posted on the Web as 2 slides/page 3 slides/page 6 slides/page1/21/15 3 Active Learning Sections (1 Credit) G04 or 107 Stimson Hall • You have each selected one section per week. • You must attend the section you have signed up for. If you don’t, your spot may be given to another student needing to attend that section. • If you find you have a conflict with another course, send an e-mail to [email protected] and follow the instructions on how to resolve it. Active Learning Sections (the third credit) Purpose: To add additional content in an active learning environment. Examples How microscopy can be used to explore the molecular organization of cells How to visualize biological molecules in three dimensions How to follow a secretory protein through the cell1/21/15 4 Joel Brown (lead TA, Section 210) Teaching Assistants (TAs) Alise Muok (sections 202, 203, 210) Soreen Cyphers (sections 201, 206, 207) Gonzalo Villarino (sections 208, 215, 216) Ben Fair (sections 204, 205, 211) Samantha Mentch (sections 209, 215, 216) Lucy Brennan (sections 205, 206, 207) [email protected] Study Group Support The Learning Strategies Center is offering study group support for BIOMG 1350/Cell and Developmental Biology this semester, beginning Wednesday 28 January 2015. You will have the opportunity to sign up online for a weekly study group, beginning on Friday 23 January 2015 and ending on Tuesday 27 January 2015. Study groups will meet weekly for an hour and a half on Wednesday, Thursday, Friday, Saturday, and Sunday afternoons and evenings. Study group members who attend at least ten study group meetings will receive 3% credit toward their final grade in BIOMG 1350/Cell and Developmental Biology. For additional help, there are office hours at the Biology Learning Strategies Center in G-24 Stimson Hall Monday through Friday from 1:30 to 4:30 PM.