BIOL Practical = 10 marks o Pre-prac test (1 mark) o Practical (5 marks) o Post-prac test (4 marks) Labour Day (7 th March) is not a holiday

Transcription

1 BIOL10002 Practical = 10 marks Pre-prac test (1 mark) Practical (5 marks) Pst-prac test (4 marks) Labur Day (7 th March) is nt a hliday

2 Mnday, 29 February 2016 Lecture 1 1 ST FOUNDATION OF BIOLOGY Evlutin and Natural Selectin Ontgeny recapitulates Phylgeny Develpment is a fast actin replay f evlutinary ancestry Hmlgy derived frm a cmmn ancestral feature, e.g. frearm structure in varius mammals and amphibians Bigegraphy als supprts evlutin Darwin s 3 bservatins (Survival f the fittest): Individuals in a ppulatin vary (fitness) Pass n traits (fitness) t ffspring (heredity) Never enugh resurces (cmpetitin fr survival and reprductin) Evlutin is a tw-step prcess: Variability Ordering that variability by Natural Selectin 2 ND FOUNDATION OF BIOLOGY Unity f bichemical prcesses DNA all rganisms use this material t encde their blueprint DNA cntains the histry f evlutin Prteins hardware t carry ut instructins 3 RD FOUNDATION OF BIOLOGY Cell thery All living things are made f cells Every cell arse frm a pre-existing cell The cell is the fundamental unit Cells cntain DNA which is passed frm cell t cell DOMAINS There are three dmains: Eukarya Archaea (mre related t Eukarya than Bacteria is) Bacteria CELL Prkarytes (n nucleus) Eukarytes /Eukarya (nucleus) Bacteria Archaea

3 Wednesday, 2 March 2016 Lecture 2 Prkarytes Prkarytes are micrscpic They are used in fd prductin (fermented fds) DNA is cntained within a single, circular chrmsme (nucleid) attached t the plasma membrane Typical prkarytic cell: DNA, cytplasm, cell wall (peptidglycan), plasma membrane, ribsmes, pilus (hair-like structures), capsule, bacterial flagellum (tail) Ribsmes: ccur in all cells cmpsed f prteins and RNAs synthesise prteins site f translatin Prkarytic ribsmes are smaller (17-23nm) Eukarytic ribsmes are larger (25-30nm) sensitive t antibitics Prkarytic flagellum: mtility appendage, cmpsed f flagellin prtein, extracellular, lng thin filament, spins/rtates at 200rpm Prkarytes divide via binary fissin and grw expnentially Their circular chrmsme is duplicated during binary fissin Bacteria and Archaea are tw different dmains due t different DNA sequences BACTERIA Micrbime in gut (abut 2kg) Mre than 50% f xygen n earth is generated by phtsynthetic bacteria Bacteria prcess abut 70% nitrgen Bacteria als cause disease by clnising ur bdies and using up resurces N prteins (histnes) are attached t DNA Wall (peptidglycan) similar in Bacteria and Archaea Gram + bacteria cntains peptidglycan and ne surrunding membrane (stains purple; thicker walls) Gram bacteria cntains peptidglycan and tw surrunding membranes (des nt stain; thinner walls)

4 ARCHAEA Archaea d nt cause any diseases Prteins (histnes) are attached t DNA Wall (peptidglycan) similar in Bacteria and Archaea Prkarytes Micrscpic, can nly be seen with an electrn micrscpe Lack a nucleus Eukarytes Can be large and multicellular, smetime can be seen by the naked eye Have a nucleus, duble membrane/nuclear envelpe, nuclear pres, cntains nuclelus where ribsmal genes are transcribed Divisin f labur in the cytplasm Endmembrane system (system f membranes inside cell) Endplasmic Reticulum, Glgi cmplex Cytskeletn (micrtubules, micrfilaments, intermediate filaments) Mtr prteins and mvement Histnes Single, circular chrmsme Lng linear strand f DNA cvered in histnes (chrmatin) Different rganisms have different numbers f chrmsmes Transcriptin: DNA RNA t be translated in cytplasm **Suffix in is a prtein

5 Lecture 3 - Eukarytes Friday, 4 March 2016 NUCLEUS Nuclear envelpe surrunds the nucleus and prjects all thrughut the rest f the cell t frm the rugh Endplasmic Reticulum The uter side f the nuclear envelpe had ribsmes attached t it Cntains nuclear pres Lined with prteins Attached t lamina (nuclear skeletn) Evenly spaced ver nuclear envelpe Used t traffic prteins and RNAs int and ut f nucleus Lcated at site where inner membrane curls arund t becme uter membrane ENDOPLASMIC RETICULUM (ER) The ER is the heart f the endmembrane system Cntains internal cmpartments and channels, as a result f cisternae (bubbles) If ribsmes attached then called rugh, r else smth Used fr the manufacture and transprt f prteins t the surface f the cell (rugh ER) Used t make mre membrane fr the cell (smth ER) Majr functins f intracellular membranes:

6 Prvide a surface fr bichemical reactins T establish a number f cmpartments t prevent mixing T prvide a means f transprt f materials within the cell, frm ne cell t its exterir, r frm the cell t an adjacent cell GOLGI COMPLEX Cnsists f flattened stacks f membrane (cisternae) called Glgi bdies Glgi cmplex is a cllective term fr all the Glgi bdies Functinal extensins f ER Used t cllect, mdify, package and distribute mlecules synthesised in the cell Manufactures plysaccharides fr cells, by attaching them t either prtein r lipid mlecules (becme identity /recgnitin mlecules n the surface f the cell) Has three znes cis, medial and trans (where is cis is clsest t ER and trans furthest) CYTOSKELETON Nt cmpsed f membrane Allws cells t change shape and shift rganelles arund Structural elements within the cell Three majr kinds: Actin filaments made f actin prtein and gelslin (7nm) Micrtubules made f tubulin prtein; cylindrical (25nm diameter) Intermediate filaments made f vimentin prtein (10nm diameter) Interact with mtr element fr mvement Actin filaments interact with mysin mtrs (muscle cntractin, cytplasmic streaming, micrvilli)

7 Micrtubules interact with kinesin (mves ne micrtubule against anther drives flagella beating) r dynein (mves vesicles alng the micrtubule) mtrs Intermediate filaments dn t interact with any mtrs Flagellum Eukarytic flagella beat instead f rtating Cnsists f micrtubules and dynein mtrs Whip-like mvement ccurs when adjacent micrtubules slide against ne anther, anchred by dynein mtrs Cytskeletal parts are being used t build nanmachines