BIO105K tutoring Thursdays 1:00 – 2:00 in the Fish Bowl = room 153 Science Building Sam Giles

Day DateSubjectTo be read prior to this class period: M1/14 no class - Snow Day! W1/16 Evolution: Unity and DiversityChapter 1 M1/21no class – Rev. Martin Luther King, Jr. Day W1/23Water and the Chemical Environment Chapter 2 (except pp30-35) M1/28Quiz #1 on Ch. 1 and parts of Ch. 2 and related lectures/handouts (no make ups for missed quiz) Cell Membranes Chapter 6 W1/30Macromolecules Chapter 3 (except pp63-69) M2/4Macromolecules W2/6Quiz #2 on Ch. 3 and 6 and related lectures/handouts (no make ups for missed quiz) The CellChapter 7 M2/11Bioenergetics W2/13Cell Respiration Chapter 9 M2/18no class - Winter Break W2/20no class - Winter Break M2/25EXAM I Chapters 1, 6,7, parts of 2, 3

Aquaporin protein makes a water channel through the cell (plasma) membrane.

The function of Aquaporin is to allow the passive diffusion of water across the cell membrane. The structure of Aquaporin is a donut and water goes through the donut hole. Aquaporin increases the rate of osmosis.

Chapter 3 is about protein structure and function. In Chapter 3, the material on pages is not really covered until after the first test. That means you need to read it now but you don’t need to study it until after the first test. Also, I will talk about this material in class but not until after the first test. The example will we use is the protein Aquaporin.

Major Sites of Expression and Function of Human Aquaporin Aquaporin-0 Eye: lens fiber cellsFluid balance within the lens Aquaporin-1 Red blood cellsOsmotic protection Kidney: proximal tubuleConcentration of urine Eye: ciliary epitheliumProduction of aqueous humor Brain: choriod plexusProduction of cerebrospinal fluid Lung: alveolar epithelial cellsAlveolar hydration state Aquaporin-2 Kidney: collecting ductsMediates antidiuretic hormone activity Aquaporin-3 Kidney: collecting ducts Reabsorbtion of water into blood Trachea: epithelial cells Secretion of water into trachea Aquaporin-4 Kidney: collecting ducts Reabsorbtion of water Brain: ependymal cellsCSF fluid balance Brain: hypothalamusOsmosensing function? Lung: bronchial epitheliumBronchial fluid secretion Aquaporin-5 Salivary glandsProduction of saliva Lacrimal glandsProduction of tears Aquaporin-6 KidneyVery low water permiability; function? Aquaporin-7 Testis and sperm Aquaporin-8 Testis, pancreas, liver, others Aquaporin-9 Leukocytes

Aquaporin creates a channel through the cell membrane that only lets H O through. 2

Some examples of endocytosis and exocytosis: 1) Aquaporin-2 in human kidney cells 2) neurotransmitter vesicles in all human nerve cells 3) phagocytosis of bacteria by human white blood cells 4) receptor-mediated endocytosis and cholesterol traffic in humans membrane traffic in cells

Some examples of endocytosis and exocytosis: 1) Aquaporin-2 in human kidney cells 2) neurotransmitter vesicles in all human nerve cells 3) phagocytosis of bacteria by human white blood cells 4) receptor-mediated endocytosis and cholesterol traffic in humans membrane traffic in cells

Some examples of endocytosis and exocytosis: 1) Aquaporin-2 in human kidney cells 2) neurotransmitter vesicles in all human nerve cells 3) phagocytosis of bacteria by human white blood cells 4) receptor-mediated endocytosis and cholesterol traffic in humans membrane traffic in cells

Some examples of endocytosis and exocytosis: 1) Aquaporin-2 in human kidney cells 2) neurotransmitter vesicles in all human nerve cells 3) phagocytosis of bacteria by human white blood cells 4) receptor-mediated endocytosis and cholesterol traffic in humans membrane traffic in cells

Low-density lipoprotein (LDL) belongs to the lipoprotein particle family. Diameter is about 22 nm, Mass is about 3 million Daltons (one Hydrogen atom = 1 Dalton) But vary in size (A few large LDL are healthier than many small LDL.) Each LDL contain: 1) one B-100 protein molecule (It’s big: 4536 amino acid residues) B-100 binds to the LDL receptor on cells. 2) a highly-hydrophobic core consisting of linoleate, a fatty acid, and about 1500 cholestrol molecules 3) surrounded by a shell of phospholipids