* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Topic: Types of Cells and Membranes
Survey
Document related concepts
Membrane potential wikipedia , lookup
Cell growth wikipedia , lookup
Tissue engineering wikipedia , lookup
Cell nucleus wikipedia , lookup
Extracellular matrix wikipedia , lookup
Cellular differentiation wikipedia , lookup
Cell culture wikipedia , lookup
Signal transduction wikipedia , lookup
Cell encapsulation wikipedia , lookup
Cytokinesis wikipedia , lookup
Cell membrane wikipedia , lookup
Organ-on-a-chip wikipedia , lookup
Transcript
All Organisms Are Made of Cells The Cell Theory All living things are composed of cells Cells are the basic unit of structure and function in living things All cells come from preexisting cells Overview Of Animal & Plants Organelle Plasma membrane “Mini-organ” Most are membrane bound & perform specific functions Outer covering that defines the boundary Regulates things going in and out Crucial for homeostasis Overview of Plant & Animal Cells Nucleus Cytoplasm Membrane bound structure that houses the DNA Fluid that fills entire cell and suspends the organelles Two Major Classes of Cells Prokaryotic Cells Lack a nucleus and other membrane bound organelles Cell wall Bacteria Archaea Earliest cells in Earth’s fossil record Two Major Classes of Cells Eukaryotic Cells True nucleus Membrane bound organelles Much bigger in size Is It Alive? Viruses ? Cell Size Some characteristics of life Smallest infectious agents Composed of mostly protein and genetic material Coat called capsid Some have envelope similar to cell membrane Structure of Cell Membrane Membrane Structure Polar Group Hydrophilic head (polar) Phosphate fatty acid chain fatty acid chain Glycerol Phospholipid molecule Phosphate head Hydrophilic Contains arrangement of atoms attached to glycerol including phosphate group Lipid tail Hydrophobic Two fatty acid chains Hydrophobic tail (non-polar) Structure of Cell Membrane Organization of phospholipids Bilayer (2 layers) Hydrophobic tails make up inside layer Hydrophilic heads face extracellular space and intra-cellular space Structure of Cell Membrane Proteins within the membrane Enzymes- carry out reactions Facilitate communication between cells and allows for recognition between cells Assists in the transport of molecules across the membrane (like water & sugars) Membranes Regulate the Traffic of Molecules 2 ways materials such as water, salts, sugar, and nutrients move across the cell membrane, in order to maintain homeostasis PASSIVE TRANSPORT 1. Passive transport 2. Active transport Molecules move from an area of high concentration to an area of low concentration No energy required Equilibrium Movement of molecules continues, across the membrane, but at the same rate in both directions Molecules are equally dispersed BALANCE Types of Passive Transport Simple diffusion: Small molecules (oxygen & carbon dioxide) pass through the membrane from an area of high concentration to an area of low concentration Facilitated diffusion: Larger molecules use protein channels to move across the membrane from an area of high concentration to an area of low concentration http://www.biology.com/ Moving Molecules against a Gradient ACTIVE TRANSPORT When molecules are moved from an area of lower concentration to area of higher concentration Cell expends energy Usually performed to prevent equilibrium from occurring Example: Neuron Passive Transport Continued Osmosis Solutions Passive transport of water across a selectively permeable membrane Water moves from an area of high concentration to an area of low concentration A solution is made up of two things : Solute and Solvent Solute: Substance in a solution that is dissolved & present in a lesser amount Solvent: Substance in a solution that dissolves the other substance & is present in a greater amount Types of solutions Hypertonic solution Hypotonic solution Isotonic solution Hyper = over Hypertonic solution is a solution that has a high concentration of solutes • Hypo= under Hypotonic solution is a solution that has a low concentration of solutes • Iso= same Isotonic solutions are ones that have an equal concentration of solutes and water in and outside of the cell Osmosis in Different Cells Turgor Pressure: The pressure produced inside the cell from a hypotonic solution Plasmolysis: When the cell membrane shrinks away from the cell wall. Organs of the Urinary system- Kidneys Ureters Urinary bladder Urethra Chapter 32.2 Urinary System 4 Organs Kidneys 2 Bean shaped structures Excrete waste products & regulate water and salt balance Filter the blood Produce urine = Liquid composed of water, urea, and other nitrogen containing waste products Ureters (2) Tubes that extend from each kidney carrying urine to the urinary bladder Urinary System 4 Organs Urinary Bladder Collapsible sac that temporarily holds urine until it is eliminated from the body Urethra Urine leaves the bladder through another tube called the urethra Urinary System Primary Goal of the Kidney Excrete waste products and regulate water and salt balance Two Roles Clean out toxins from blood Restore water 4 Steps Involved when Blood is Processed & Urine is Excreted Step #1 = Filtration Blood pressure forces water and small solutes, including urea, into the Bowman’s Capsule Step #2 = Reabsorption Active Transport reabsorbs Glucose, amino acids, and other ions from the filtrate back into the blood Water solution left behind is hypotonic causing osmosis to move water back into the blood 4 Steps Involved when Blood is Processed & Urine is Excreted Step #3: Secretion The following substances are transported from the blood back into the filtrate Nitrogenous waste products • Urea • Uric Acid • Toxins Excess Water 4 Steps Involved when Blood is Processed & Urine is Excreted Step #4: Excretion Remaining filtrate is transported to the bladder to leave the body Regulating Water Balance Mechanisms of homeostasis regulate the amount of water reabsorbed by the kidney Example: Negative Feedback Loop How the body responds to a stimulus, in order to create a balance again… Regulating Water Balance Decrease water level in your body Increase concentration of solutes in your blood Thirst center in your brain is activated Motivates you to drink ADH (anti-diuretic hormone) is released ADH travels in the blood to the kidneys stimulates the nephrons to reabsorb more water Result: Decrease in solute concentration in the blood to within the normal range Water content of urine decreases Yellow; concentrated Regulating Water Balance Drink too much water Solute concentration in blood drops below the normal range Less ADH is released from the brain Lower level of ADH, decreases the amount of water reabsorbed in the nephrons Result: Urine contains more water lighter in color Transporting Large Molecules Endocytosis Moving large molecules into the cell within vesicles Vesicles: Small membrane bound sacs specialized in moving materials in and out of cell Exocytosis o Moving large molecules out of the cell within vesicles