Mcb 150 Exam 1 Ultimate Review - Histological Lecture Notes On Administrative Stuff PDF

Preview

Summary

Download Mcb 150 Exam 1 Ultimate Review - Histological Lecture Notes On Administrative Stuff PDF

Description

Lecture 1 Admin stuf Lecture 2 1700s Carl Linnaues  

Genus species naming system Taxonomy

2 types of cells: 





Eukaryotes o Has a nucleus o Animal cell o Plant cells have cell walls and chloroplasts o Plasma membrane-separates cell from extracellular space o Organelles are compartmentalized o Mitochondria o Nucleus  Has a nuclear envelope  Double membrane o Lysosome o ER  Smooth  rough o golgi Prokaryotes o Does not have a nucleus o Have a cell wall- usually, but not always present o Plasma membrane-every cell has to have a plasma membrane o Cytoplasm inside the cell o Nucleoid region-not separated by a membrane  Just hanging out in the cytoplasm  Where genetic material is found  Usually a single chromosome Domains of Life o Until 1977- superkingdoms  Prokaryotes  w/o nuclear membrane and membrane bound organelles  eukaryotes  w/ a nuclear membrane and membrane bound organelles o Carl Woese- UIUC  Compared small subunit rRNAs  Essential in every organism

 





Closer the rRNAs, the closer they are related Why rRNA?  Evolutionarily ancient  Found in all organisms  Have the same function in all organism  Highly conserved o Evolved slowly o Any changes are very important Conclusion  Prokaryotes are 2 distinct groups of organisms o Bacteria- true bacteria like E. coli  Found everywhere o Archaea  “ancient” prokaryotes  Found in extreme habitats  Extreme heat, pressure, acids, salts, gases  Archaea more closely related to eukaryotes than to bacteria  New TREE OF LIFE o 3 DOMAINS  Bacteria + archaea  No nuclear membrane  No membrane bound organelles  Typically 1-10 microns  1 chromosome o Mostly circular  Eurkarya  Nuclear membrane  Has organelles  10-100 microns  More than 1 chromosome  Linear chromosomes

Intro to Cells o Cells need to be compartmentalized o Life is composed of cells o Basic tenets of cell theory  Cell is fundamental unit of life  All organisms are composed of one or more cells  All cells come from pre-existing cells o Why are cells so small?  As the size increases, the SA to V ratio decreases  Need SA for difusion  Need V for storage  Large enough to sustain metabolism  But might be less efficient

o

o

Relative Size  Cells are about 100-10 micrometers  Scale of life!!!!!!! Microscopy  Light microscope  Good for seeing cells and some other subcellular stuf  Electron microscopy  TEM  SEM o More 3-D perspective  Darker images= dense material

Basic Bacterial Structure  



  

Some cells (plants, most prokaryotes) have a rigid cell wall o Providing shape and protection Every cell is surrounded by a plasma membrane o Allows cells to maintain a constant internal environment o Place where signals are received or sent o Acts as a selectively permeable barriers Outside layer is capsule layer o Thick mucusy layer of complex carbs and proteins o Gives cell extra layer of protection o Allow it to stick to other stuf o Not every bacterial cell has a capsule o Can sometimes be removed o Non-essential, but might have advantage if it has it Next is the cell wall Next is plasma membrane Inside is cytoplasm o In the cytoplasm, there are ribosomes o Also has nucleoid  Contain DNA

Lecture 3 Basic Structure of the Eukaryotic Cell; Intro to Carbs      

Plasma membrane o About 15nm wide Nucleus o About 10 microns in diameter Mitochondria Rough ER Smooth ER Golgi Apparatus

 











Ribosomes o Polyribosomes 4 types of biological macromolecules o Protiens o Nucleic acids o Carbohydrates o Lipids Cell composition o 70% water o 26% macromolecules o Rest other stuf Macromolecule composition o Proteins o Nucleic acids o Carbs o Lipids Macromolecules are made up of monomers o Proteins-amino acids o Nucleic acids- nucleotides o Polysaccharides- monosaccharides o Lipids- fatty acids o Polymerization- bonding together of monomers Condensation- dehydration synthesis o Release water o Release energy Hydrolysis o Use a water molecule o Input energy to break the bond o Delta G < 0 negative o Exergonic o Catabolic o Spontaneous o Energy of products is less than energy of reactants

Lecture 4 Carbohydrates 



Uses: o

Energy sources, structural roles like insect exoskeletons and cell walls or cell identification and recognition General formula CnH2nOn with a backbone of H-C-OH

o o o



 some monosaccharides have identical formulas but diferent structures- isomers o aldose vs. ketose

 Aldose  Glucose  Galactose o Ketose  Fructose Other monosaccharides have similar formulas and structures, but not related functions o Deoxyribose vs. ribose Trioses o 3-carbon sugar  Aldose- glyceraldehyde  Ketose- dihydroxyacetone Pentoses o 5-carbon sugar o

 



Monosaccharides are typically found with 3,5, or 6 carbons Circularization of glucose

 

 









 Aldose- ribose, deoxyribose  Ketone- xylulose When 2 monosaccharides come together, they form a glycosidic linkage 4 most common disaccharides o Lactose  Glucose + galactose o Maltose  2 alpha glucoses o Cellobiose  Beta glucose + another glucose o Sucrose  Glucose + fructose Whenever disaccharides form, 1 water molecule is taken out Carbs can be modified o Can link to other molecules  When covalently linked to membrane proteins or lipids, carbs act as identification and recognition molecules (chemical markers)  Blood typing  Glycoprotein  Glycolipid o Addition of chemical groups  Ex) glucose  glucosamine Polysaccharides serve as chemical sources of energy or structural compounds o Cellulose o Starch o Glycogen Cellulose o Most abundant organic compound on earth o Found in plant cell walls o Linear, unbranched polymer of glucose o H-bonds are important o Linked by beta 1,4 glycosidic linkages o Structure o Monomers are beta glucose molecules Starch o Found in deez nuts, roots and stems of plant o Energy storage in plants o Helical o Unbranched or loosely branched polymers if glucose o Monomers in chain linked w/ alpha 1,4 glycosidic linkages o Chains connected w/ alpha 1,6 glycosidic linkages o Monomers are alpha glucoses Glycogen

o o o o

Energy storage in animals Helical, highly branched Same linkages as starch Monomers are alpha glucoses

Lecture 5 Proteins    



We are the product of our proteins and protein activity Study of proteins- proteomics Most of the dry weight in cells Uses of proteins o Movement  Actin/myosin in muscles o Defense  Antibodies o Structure  Keratin o Transport  Hemoglobin o Signaling  Glucagon o Catalysis/regulation/metabolism Amino acids are the monomers o Basic structure





 Central carbon  Amino- N terminus  Carboxyl- C terminus  R group is the only part that difers between amino acids  R group- side chain o Covalent bonds are called peptide bonds  Ribosomes link amino acids by joining the NH3 + group with the COO- group  Always in the NC direction o Protein- polypeptide with a purpose Amino acids

20 diferent amino acids R- groups grouped by charge (4 groups)  Uncharged, but polar  All have an oxygen o Which makes it polar  Uncharged and non-polar (hydrophobic)  All are either carbon or hydrogen o No big change in electronegativity  Positively charged (basic)  Proton acceptor  Negatively charged (acidic)  Proton donor Primary and Secondary structures o Primary structure  Linear sequence of amino acids  N C  All proteins have a unique primary structure o Secondary structure  First level of folding  Stabilized by H-bonds between peptide backbone linkages  Because peptide backbone is polar o N-H bond is partially + o C=O is partially – o These two form H-bonds between the backbones  Independent of R-groups o Found in most proteins  2 basic structures  Alpha helix  Beta pleated sheet o Arrows point toward the C terminus of the primary structure  Prions  Misfolded proteins which somehow induce normal versions of that protein to fold the same (incorrect) way  Causes many diseases o Tertiary Structure  Can sometimes be final conformation for some proteins  Due to interactions between R-groups with each other and w/ backbone  H-bonds- between polar side chains  H-bonds between hydrophilic side chains and backbone  Ionic bond between an acidic and a basic amino acid  Hydrophobic clustering of non-polar side chains  Van der Waals forces  Disulfide linkages o Can only be between cysteines o o



o Only made by an enzyme Quaternary Structure  Found in proteins w/ multiple polypeptide chains (subunits)  Subunits can be same or diferent Relative strengths of stabilizing forces o Disulfide linkages- only covalent bonds o Ionic bonds- easily made and broken o Hydrogen bonds o Hydrophobic clusters o Van der waals forces o



Lecture 6 Denaturation and Enzymes 



 



  





Denature- removal or inactivation of stabilizing forces which unfolds the protein to primary structure o No peptide bonds are broken o All of secondary and tertiary structure is lost o Leads to loss of function o Caused by acids/bases, heat, detergents Most proteins are enzymes o Biological catalysts  Facilitate reactions Reactions that require energy are biosynthetic or anabolic o Condensation reactions Reactions that release energy are catabolic o Spontaneous o Hydrolysis reaction Energy diagrams o Energy of activation o Conversion of substrates into transition states and then products Delta G= free energy of reaction: o Diference in E between reactants and products Enzymes do not cause reactions which would normally not occur o Only speed up reactions Enzymes bind substrates w/ high specificity into their active sites o They will cause some change in substrate, but they usually change shape upon binding substrate  Induced fit How does substrate binding to act o Acting as a template for substrate orientation o Stressing the substrates and stabilizing the transition state o Providing a favorable microenvironment o Participating directly in the catalytic reaction Enzymes are unchanged by the reactions they catalyze



Enzymes do not change equilibrium o Only make reaching eq faster o Decrease Ea by the same amount in both directions of the reaction

Lecture 7 enzyme Optima and Inhibition; Nucleic Acids  

Most enzymes tend to be near body temperature (37 degrees C) and pH (7.0) Enzyme inhibition o Irreversible inhibitors  Permanently bind to or modify active substrate  Changing concentration of natural substrate or inhibitor has no efect  Tend to be molecules not typically encountered by that cell  Exemplify that enzymes must be unchanged o Competitive inhibition  Inhibitor physically resembles the natural substrate and occupies active site  Enzyme can’t use inhibitor as substrate- no products are formed  Can be “flooded out” by increasing concentration of natural substrate  Decreasing concentration of inhibitor also reduces probability of inhibitor finding active site  Ex) ethanol o Noncompetitive inhibition  Inhibitor molecule binds to the enzyme in a place other than the active site  Increasing substrate concentration has no efect  Reversible because inhibitor can become unbound

Nucleic Acids     

  

DNA RNA Information storage role in a cell Monomers of nucleic acids are nucleotides Phosphate-sugar-base

Base + sugar = nucleoside Pyrimidines o Cytoside o Thymine-DNA



o Uracil-RNA Purines o Adenine o Guanine

Lecture 8 Nucleic Acids; Lipids and Biomembranes 







Nts of DNA and RNA difer in 2 important ways o The nitrogenous bases found in each nucleic acid o Which 5-carbon sugar is found in each nucleic acid DNA o Deoxyribose sugar (H at 2’ carbon) o Pyrimidine bases are cytosine and thymine o Purine bases are adenine and guanine o Monomers are called dNTPs o Double-stranded RNA o Ribose sugar (OH at 2’ carbon) o Pyrimidine bases are cytosine and uracil o Purine bases are adenine and guanine o Monomers called NTPs, ribonucleoside triphosphate, ribonucleotides o Single-stranded Polymerization of nucleic acid o Phosphodiester linkage o 3’ H connects to OH in phosphate group

Lipids   



Defined by a physical property, not a chemical structure Vary widely in structure 3 primary functions o Energy storage  Triglycerides o Biomembrane composition  Phospholipids  Glycolipids o Chemical signaling  Steroids Biological membranes o Monomers  Glycerol  Fatty acids

3 fatty acids + glycerol = triglyceride  A fat  Connected with an ester linkage o 2 fatty acids + glycerol + phosphate = phospholipid  Common examples of major membrane phospholipids  Phosphatidic acid  Phosphatidylethanolamine  Phosphatidylcholine  …serine  …inositol  Sphingomyelin o Choline  Message: a lot of variety in polar head groups o Tails can vary too Phospholipids are amphipathic Phospholipids in water will spontaneously form micelles or bilayers o Bilayers have exposed edges  Will fold into liposomes Some membrane lipids are glycolipids 4th type of lipids are steroids o Can be used as circulating hormones or as membrane components o Animals cells have cholesterol in their biomembranes o Plants & fungi: diferent steroids o Bacteria: none Biomembranes are asymmetrical Biomembranes have associated proteins o Serve as a variety of function Biomembranes are selective permeable o High permeability  Small, nonpolar  Small, uncharged polar  Large, uncharged polar  Ions o Low permeability o

 

 

  

Lecture 9    

Biological membranes are fluid Experiment o Mouse and human cell Fluid- ability of molecules to move around in membranes Movement of lipids o Flex or rotation

 Very rapid Lateral shif  Rapid o Transverse difusion  Very slow  Need an enzyme  Catalyzed by flipase Fluidity is temperature dependent o Lower temperature means closer to gel phase o High temperature means closer to fluid phase Other factors to increase fluidity o High level of unsaturated fatty acids  More kinks in fatty acids o Shorter tail length of fatty acids  Less able to interact with their neighbors o Higher number of cholesterol molecules (at low temperatures)  Breaking up the interactions between the lipids o



...