BIOL 2050 1st Edition Exam 2 Study Guide Lectures 7 12 Lecture 7 February 6 Function of Macromolecules What are macromolecules and how do they occur Macromolecules are large molecules that are composed of thousands of covalently connected atoms They are formed by dehydration synthesis which occurs when two monomers bond together through the loss of a water molecule They are separated by hydrolysis which occurs when a water molecule is removed and disassembles two monomers What are carbohydrates and what are their functions Carbohydrates are sugars and the polymers of sugars They can be simple monosacchrides or they can be composed of many sugar building blocks polysaccharides Sugars Most common is Glucose Polymers of sugars have storage and structural roles Disacchride is joined by a glycosidic linkage Starch Storage polysaccharide in plants in chloroplasts and other plastids o Cellulose structural component in cell walls Glycogen storage in animals in liver and muscle cells Chitin outer skeleton of insects What are lipids and what are their functions Lipids are biological polymers that do not form polymers They are hydrophobic and are mostly hydrocarbons Fats constructed from glycerol and fatty acids Ester linkage Saturated fats no double bonds and are solid at room temperature Unsaturated Fats one or more double bond and liquid at room temperature Trans Fats Purpose energy storage in adipose cells and cushions vital organs Phospholipids two fatty acids and a phosphate group attached to a glycerol Forms the cell membrane phospholipid bilayer Steroids carbon skeleton of four fused rings Cholesterol important in animal cell membranes Lecture 8 February 9 What are proteins and what are their functions Proteins have many different functions throughout the body and account for more than 50 of the dry mass of most cells Types Enzymes Defensive Storage Transport Hormonal Receptor Motor Structural Structure Polypeptide unbranched polymers built form the same set of 20 amino acids R Group is what varies from amino acid to amino acid Peptide bonds Sequence of amino acids determines structure which then determines function What are nucleic acids and what are their functions Nucleic acids are polymers consisting of many nucleotides and serves as the blueprint for proteins Types DNA RNA Structure Polynucleotides Each nucleotide is made of a nitrogenous base a pentose sugar and one or more phosphate groups Double Helix and antiparallel Linear sequence of nucleotides in DNA molecules Lecture 9 February 11 What is the cell theory What are the two cell types Cell Theory All living things are made of cells and all cells arise from preexisting cells Cell Types Prokaryotic Eukaryotic plant animal and fungal cells along with other organisms What are the main components of Eukaryotic cells Nucleus Cytoplasm Plasma membrane Ribosomes Endoplasmic Reticulum Golgi body Vesicles Cytoskeleton Cilia and Flagella Lysosome Mitochondria Chloroplast Central vacuole Cell wall Plasmodesmata note that the chloroplast central vacuole cell wall and plasmodesmata are unique to plant cells Lecture 10 February 13 What is the basic structure of the plasma membrane Explain the fluidity The basic structure is the Fluid Mosaic Model that consists of a fluid membrane structure with various proteins embedded in it Phospholipids in the membrane that is amphipathic Fluidity phospholipids in the bilayer can move by drifting laterally o Effected by change in temperature o Solidification depends on the types of lipids Vary between species What is the role of proteins and carbohydrates in the plasma membrane Proteins are both on the surface of the membrane and are integrated through the entire membrane o They have many functions including transporting enzymatic activity cell cell recognition signal transduction intercellular joining and attaching to the cytoskeleton and extracellular matrix Carbohydrates carry out cell cell recognition through glycolipids and glycoproteins that are distinct between cells What is permeability and how does the cell regulate traffic Permeability is the rate at which molecules and substances move in and out of the cell Diffusion molecules spreading out easily Passive transport requires no energy and diffuses substances across a membrane o Uses transport proteins Active Transport uses energy to move against a concentration gradient o Ion pumps Proton Pumps Osmosis the diffusion of water from a high solute concentration to a low solute concentration What is tonicity and how does it affect a cell Tonicity the ability of a surrounding solution to cause a cell to gain or lose water Isotonic Solution concentration is the same as the inside of the cell The cell is balanced Hypertonic Solution solute concentration is greater than the inside of the cell The cell loses water and may shrivel up Hypotonic Solution solute concentration is less than that of the inside of the cell Cell gains water and may explode The regulation of the concentration of water is called osmoregulation o Different organisms prefer different levels of concentration What is the difference between Endocytosis and Exocytosis Both functions involve transporting large molecules but endocytosis involves taking in large macromolecules into the cell by forming vesicles from the plasma membrane Exocytosis includes transporting large molecules out of the cell