BIOSC 150 1st Edition Exam 1 Study Guide Lectures 1 16 Lecture 1 Study of Lipids Lipid a catchall term for carbon containing compounds that are found in organisms and are largely nonpolar and hydrophobic meaning they don t dissolve in water Lipids are hydrocarbons molecules that contain only carbon and hydrogen The reason lipids don t dissolve in water is because their hydrocarbon component Where do you find lipids in a cell Cell membranes Huge droplets in adipose cells that are used for energy storage cushioning or insulation Large droplets in mammary cells Lecture 2 Study of DNA Transcription the process from DNA to RNA process occurs in the nucleus Small differences in DNA can change an entire organism Not all cells contain the same DNA antibodies will cause slight shifts in DNA strands Two nucleic acids run anti parallel in a DNA double helix Base pairing occurs between DNA and RNA and allows for transcription to occur and the formation of hydrogen bonds Lecture 3 Study of Proteins Proteins have multiple structures and therefore many functions including catalysis transportation defense structure movement signaling and regulate gene expression Secondary Structure some regions fold into helices or pleats Tertiary structure bending and folding determined by R group interactions Proteins always build from 1 prime to 3 prime with regards to structure Lecture 4 Study of Proteins It is known that the structure of a protein is essential because if the protein is unfolded it cannot perform the same function Protein structure and function is diverse Enzymes contain active site clefts this is where substrates are bonded and its job is done Detergent hides hydrophobic groups so water doesn t push it back together Hemoglobin a protein that transports oxygen and is composed of 4 polypeptides coded for by 2 DNA genes Lecture 5 Study of Hemoglobin Sickle cells block blood flow leading to pain and swelling a Sickle cells are sticky and stiff b The stiffness and stickiness leads to the blockage Oxygen concentration is high in the lungs and low in peripheral tissues Sickle red blood cells are filled with fibers normal cells are not filled with fibers One may perform a test to determine which biomolecule makes up the sickle cell a The cell could be composed of lipids carbs proteins or nucleic acid b A possible test would include using specific dyes to identify the biomolecule c Another test would include adding particular reagents to the cell The fibers are composed of abnormal hemoglobin protein Lecture 6 Study of Membranes Movement across the membrane can be measured Experiments measure membrane permeability Chemicals establish equilibrium across a permeable membrane by random movements Membranes also contain embedded proteins and glycoproteins Membrane proteins do many jobs 1 2 3 4 Transporters Anchors Receptors Enzymes Membranes are highly selective Lecture 7 Study of Disease Cystic Fibrous What are the symptoms of cystic fibrosis a b c d Appearance of being emaciated Sweat is salty Trouble breathing Mucous build up in lungs What is the cause of cystic fibrosis a Hydrophobic chain trans membrane domains b Chlorine ion unable to escape the cell membrane How to isolate the membrane protein 1 2 3 Add detergents Binding takes place by the detergent Isolation of the protein bound CFTR the protein responsible for cystic fibrosis purification is analyzed by gel electrophoresis Lecture 8 Tenets of Cell Theory Tenets of cell theory 1 Cells are the fundamental units of life 2 All organisms are composed of cells 3 All cells come from pre existing cells The tree of life 1 Bacteria Achaea Prokaryotes 2 Eukaryotes How can we study cells 1 Microscopes 2 Breaking the cell take out the contents of the cell and fractionate Electron Microscopy for detailed analysis of subcellular structures and surfaces a Transmission electron microscopy high magnification of cross sections b Scanning electron microscopy lower magnification of surfaces Lecture 9 Study of Subcellular Structures Three types of filamentous proteins comprising the cytoskeleton 1 Microfilaments actin small diameter polymer made of actin monomers 2 Intermediate Filaments intermediate diameter polymer made of various proteins depending on the cell type 3 Microtubules large diameter polymer made of the proteins alpha and beta tubulin Cytoskeletal filaments are long chains made up of repeating protein subunits monomers Microfilaments A subunit of actin Chain wounded to form a double helix long strands Two forms of actin 1 Globular 2 Filamentous are constantly interconverting Requires energy in the form of ATP Lecture 10 Study of Subcellular Structures Intermediate filaments provide the cell with tensile strength 1 2 3 4 5 Long chains more elongated than actin Huge diverse array Rope like structure Good to resist tense forces Can distinguish different cell types IF cell type can help to show the origin of the cell type therefore determining a treatment plan for cancer in particular Metastatic cancer Demosomes intermediate filaments that are critical for cell cell interactions Hemidesomes intermediate filaments critical for cell substratum interactions Lecture 11 Study of Protein Synthesis Steps in Protein Synthesis 1 2 3 4 Transcribe information encoded by DNA into mRNA Translate information encoded by mRNA into proteins Fold and modify proteins Deliver proteins to their proper place within or outside the cell The Nucleus Largest organelle Functions DNA replication transcription mRNA processing ribosome assembly Nuclear envelope double membrane selectively permeable barrier Nuclear Envelopes Roles 1 2 3 4 Regulates traffic to protect and separate Imports nucleotides for DNA and proteins Exports mRNA and ribosomes All traffic in and out of nucleus goes through the nuclear pores Nuclear pores connection between the nucleus and nuclear envelope Lecture 12 Lysosomes and SER Lysosomes cell s recycling center of acid hydrolases All lysosomal hydrolases are tagged with mannose 6 phosphate in the Golgi Lysosomes recycle damaged organelles and degrade engulfed partciles Smooth ER VS Rough ER The SER does not contain ribosomes The SER is the primary site of phospholipid synthesis The SER is the site of cholesterol and steroid synthesis The SER is an important site for calcium storage The SER is critical for detoxifying chemicals Lecture 13 Study of Signaling G proteins couple receptors G proteins bind to GTP G proteins transduce Transmembrane receptors can be