PowerPoint ® Lecture Slide Presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings PART B 3 Cells

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Objectives  Discuss various cell connections  Compare the processes of diffusion, dialysis, facilitated diffusion, osmosis, and filtration.  Discuss and compare the factors that determine potential osmotic pressure of electrolyte and nonelectrolyte solutions.  Discuss the active cell transport mechanisms responsible for movement of some materials through cell membranes

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Objectives  Describe the molecular structure of DNA  Discuss how genes control protein synthesis and determine hereditary characteristics  Compare and Contrast mitosis and meiosis  Discuss cellular diseases

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cell Physiology: Membrane Transport  Membrane transport—movement of substances into and out of the cell  Two basic methods of transport  Passive transport  No energy is required  Active transport  Cell must provide metabolic energy (ATP)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Solutions and Transport  Solution—homogeneous mixture of two or more components  Solvent—dissolving medium; typically water in the body  Solutes—components in smaller quantities within a solution  Intracellular fluid—nucleoplasm and cytosol  Interstitial fluid—fluid on the exterior of the cell

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Selective Permeability  The plasma membrane allows some materials to pass while excluding others  This permeability influences movement both into and out of the cell

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes  Diffusion  Particles tend to distribute themselves evenly within a solution  Movement is from high concentration to low concentration, or down a concentration gradient Figure 3.9

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes  Types of diffusion  Simple diffusion  An unassisted process  Solutes are lipid-soluble materials or small enough to pass through membrane pores

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes Figure 3.10a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes  Types of diffusion (continued)  Osmosis—simple diffusion of water  Highly polar water molecules easily cross the plasma membrane through aquaporins

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes Figure 3.10d

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes  Facilitated diffusion  Substances require a protein carrier for passive transport  Transports lipid-insoluble and large substances

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes Figure 3.10b–c

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Passive Transport Processes  Filtration  Water and solutes are forced through a membrane by fluid, or hydrostatic pressure  A pressure gradient must exist  Solute-containing fluid is pushed from a high-pressure area to a lower pressure area

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes  Substances are transported that are unable to pass by diffusion  Substances may be too large  Substances may not be able to dissolve in the fat core of the membrane  Substances may have to move against a concentration gradient  ATP is used for transport

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes  Two common forms of active transport  Active transport (solute pumping)  Vesicular transport  Exocytosis  Endocytosis  Phagocytosis  Pinocytosis

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes  Active transport (solute pumping)  Amino acids, some sugars, and ions are transported by protein carriers called solute pumps  ATP energizes protein carriers  In most cases, substances are moved against concentration gradients

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Sodium-Potassium Pump

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.11 Extracellular fluid Cytoplasm Loss of phosphate restores the original conformation of the pump protein. K + is released to the cytoplasm and Na + sites are ready to bind Na + again; the cycle repeats. Binding of cytoplasmic Na + to the pump protein stimulates phosphorylation by ATP, which causes the pump protein to change its shape. The shape change expels Na + to the outside. Extracellular K + binds, causing release of the phosphate group. ADP Na + K+K+ K+K+ K+K+ K+K+ P P P ATP

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.11, step 1 Extracellular fluid Cytoplasm Binding of cytoplasmic Na + to the pump protein stimulates phosphorylation by ATP, which causes the pump protein to change its shape. ADP Na + P ATP

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.11, step 2 Extracellular fluid Cytoplasm Binding of cytoplasmic Na + to the pump protein stimulates phosphorylation by ATP, which causes the pump protein to change its shape. The shape change expels Na + to the outside. Extracellular K + binds, causing release of the phosphate group. ADP Na + K+K+ K+K+ P P P ATP

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Figure 3.11, step 3 Extracellular fluid Cytoplasm Loss of phosphate restores the original conformation of the pump protein. K + is released to the cytoplasm and Na + sites are ready to bind Na + again; the cycle repeats. Binding of cytoplasmic Na + to the pump protein stimulates phosphorylation by ATP, which causes the pump protein to change its shape. The shape change expels Na + to the outside. Extracellular K + binds, causing release of the phosphate group. ADP Na + K+K+ K+K+ K+K+ K+K+ P P P ATP

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes  Vesicular transport  Exocytosis  Moves materials out of the cell  Material is carried in a membranous vesicle  Vesicle migrates to plasma membrane  Vesicle combines with plasma membrane  Material is emptied to the outside

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Exocytosis Figure 3.12a

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Exocytosis Figure 3.12b

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes  Vesicular transport (continued)  Endocytosis  Extracellular substances are engulfed by being enclosed in a membranous vescicle  Types of endocytosis  Phagocytosis—“cell eating”  Pinocytosis—“cell drinking”

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a Recycling of membrane and receptors (if present) to plasma membrane Cytoplasm Extracellular fluid Plasma membrane Detachment of vesicle Vesicle containing ingested material Vesicle Vesicle fusing with lysosome for digestion Release of contents to cytoplasm Lysosome Transport to plasma membrane and exocytosis of vesicle contents Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a, step 1 Cytoplasm Extracellular fluid Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a, step 2 Cytoplasm Extracellular fluid Plasma membrane Detachment of vesicle Vesicle containing ingested material Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a, step 3 Cytoplasm Extracellular fluid Plasma membrane Detachment of vesicle Vesicle containing ingested material Vesicle Vesicle fusing with lysosome for digestion Lysosome Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a, step 4 Cytoplasm Extracellular fluid Plasma membrane Detachment of vesicle Vesicle containing ingested material Vesicle Vesicle fusing with lysosome for digestion Release of contents to cytoplasm Lysosome Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a, step 5 Cytoplasm Extracellular fluid Plasma membrane Detachment of vesicle Vesicle containing ingested material Vesicle Vesicle fusing with lysosome for digestion Release of contents to cytoplasm Lysosome Transport to plasma membrane and exocytosis of vesicle contents Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13a, step 6 Recycling of membrane and receptors (if present) to plasma membrane Cytoplasm Extracellular fluid Plasma membrane Detachment of vesicle Vesicle containing ingested material Vesicle Vesicle fusing with lysosome for digestion Release of contents to cytoplasm Lysosome Transport to plasma membrane and exocytosis of vesicle contents Plasma membrane Ingested substance Pit (a)

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Active Transport Processes: Endocytosis Figure 3.13b–c

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cell Life Cycle  Cells have two major periods  Interphase  Cell grows  Cell carries on metabolic processes  Cell division  Cell replicates itself  Function is to produce more cells for growth and repair processes

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings DNA Replication  Genetic material is duplicated and readies a cell for division into two cells  Occurs toward the end of interphase  DNA uncoils and each side serves as a template

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings DNA Replication Figure 3.14

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis  Gene—DNA segment that carries a blueprint for building one protein  Proteins have many functions  Building materials for cells  Act as enzymes (biological catalysts)  RNA is essential for protein synthesis

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Role of RNA  Transfer RNA (tRNA)  Transfers appropriate amino acids to the ribosome for building the protein  Ribosomal RNA (rRNA)  Helps form the ribosomes where proteins are built  Messenger RNA (mRNA)  Carries the instructions for building a protein from the nucleus to the ribosome

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Transcription and Translation  Transcription  Transfer of information from DNA’s base sequence to the complimentary base sequence of mRNA  Three-base sequences on mRNA are called codons

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Transcription and Translation  Translation  Base sequence of nucleic acid is translated to an amino acid sequence  Amino acids are the building blocks of proteins

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis DNA mRNA rRNA · · · tRNA

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16, step 1 Nucleus (site of transcription) DNA mRNA specifying one polypeptide is made on DNA template Cytoplasm (site of translation ) Nuclear pore Nuclear membrane mRNA

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16, step 2 Nucleus (site of transcription) DNA mRNA specifying one polypeptide is made on DNA template mRNA leaves nucleus and attaches to ribosome, and translation begins Cytoplasm (site of translation ) Nuclear pore Nuclear membrane mRNA Small ribosomal subunit Large ribosomal subunit Codon UG C CAU

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16, step 3 Nucleus (site of transcription) DNA mRNA specifying one polypeptide is made on DNA template mRNA leaves nucleus and attaches to ribosome, and translation begins Synthetase enzyme Amino acids Cytoplasm (site of translation ) Correct amino acid attached to each species of tRNA by an enzyme Nuclear pore Nuclear membrane mRNA Small ribosomal subunit Large ribosomal subunit Codon UG C CAU

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16, step 4 Nucleus (site of transcription) DNA mRNA specifying one polypeptide is made on DNA template mRNA leaves nucleus and attaches to ribosome, and translation begins Synthetase enzyme Amino acids Cytoplasm (site of translation ) Correct amino acid attached to each species of tRNA by an enzyme Nuclear pore Nuclear membrane mRNA Small ribosomal subunit tRNA “head” bearing anticodon Large ribosomal subunit Incoming tRNA recognizes a complementary mRNA codon calling for its amino acid by binding via its anticodon to the codon Codon UG C CAU

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16, step 5 Nucleus (site of transcription) DNA mRNA specifying one polypeptide is made on DNA template mRNA leaves nucleus and attaches to ribosome, and translation begins Synthetase enzyme Amino acids Cytoplasm (site of translation ) Correct amino acid attached to each species of tRNA by an enzyme Growing polypeptide chain Nuclear pore Nuclear membrane mRNA As the ribosome moves along the mRNA, a new amino acid is added to the growing protein chain Direction of ribosome advance; ribosome moves the mRNA strand along sequentially as each codon is read Small ribosomal subunit tRNA “head” bearing anticodon Large ribosomal subunit Peptide bond Incoming tRNA recognizes a complementary mRNA codon calling for its amino acid by binding via its anticodon to the codon Codon Ala Phe Ser Gly Met CGG GCUCAG C CAU

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Protein Synthesis Figure 3.16, step 6

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Events of Cell Division  Mitosis—division of the nucleus  Results in the formation of two daughter nuclei  Cytokinesis—division of the cytoplasm  Begins when mitosis is near completion  Results in the formation of two daughter cells

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis  Prophase  First part of cell division  Centrioles migrate to the poles to direct assembly of mitotic spindle fibers  DNA appears as double-stranded chromosomes  Nuclear envelope breaks down and disappears

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis  Metaphase  Chromosomes are aligned in the center of the cell on the metaphase plate Metaphase Prometaphase

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis  Anaphase  Chromosomes are pulled apart and toward the opposite ends of the cell  Cell begins to elongate

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis  Telophase  Chromosomes uncoil to become chromatin  Nuclear envelope reforms around chromatin  Spindles break down and disappear

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis  Cytokinesis  Begins during late anaphase and completes during telophase  A cleavage furrow forms to pinch the cells into two parts

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15 Centrioles Plasma membrane Interphase Early prophase Late prophase Nucleolus Nuclear envelope Spindle pole Chromatin Centrioles Forming mitotic spindle Centromere Chromosome, consisting of two sister chromatids Fragments of nuclear envelope Centromere Spindle microtubules MetaphaseAnaphase Telophase and cytokinesis Daughter chromosomes Sister chromatids Nuclear envelope forming Nucleolus forming Spindle Metaphase plate Cleavage furrow

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 1 Centrioles Plasma membrane Interphase Nucleolus Nuclear envelope Chromatin

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 2 Centrioles Plasma membrane InterphaseEarly prophase Nucleolus Nuclear envelope Chromatin Centrioles Forming mitotic spindle Centromere Chromosome, consisting of two sister chromatids

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 3 Centrioles Plasma membrane InterphaseEarly prophaseLate prophase Nucleolus Nuclear envelope Spindle pole Chromatin Centrioles Forming mitotic spindle Centromere Chromosome, consisting of two sister chromatids Fragments of nuclear envelope Centromere Spindle microtubules

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 4 Metaphase Sister chromatids Spindle Metaphase plate

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 5 MetaphaseAnaphase Daughter chromosomes Sister chromatids Spindle Metaphase plate

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 6 MetaphaseAnaphaseTelophase and cytokinesis Daughter chromosomes Sister chromatids Nuclear envelope forming Nucleolus forming Spindle Metaphase plate Cleavage furrow

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Stages of Mitosis Figure 3.15, step 7 Centrioles Plasma membrane Interphase Early prophase Late prophase Nucleolus Nuclear envelope Spindle pole Chromatin Centrioles Forming mitotic spindle Centromere Chromosome, consisting of two sister chromatids Fragments of nuclear envelope Centromere Spindle microtubules Metaphase Anaphase Telophase and cytokinesis Daughter chromosomes Sister chromatids Nuclear envelope forming Nucleolus forming Spindle Metaphase plate Cleavage furrow

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meoisis  Start with a cell of 46 chromosomes and end up with 4 cells of 23 chromosomes  happens only in the egg and sperm cell  goes through meiosis I and meiosis II

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meiosis I  Interphase- everything duplicates  Prophase- chromosomes cross over and exchange information  Metaphase- line up down middle  Anaphase- split  Telephase- cell pinches and two cells form with 23 chromosomes

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Meiosis II  Interkinesis- very quick, no replication  Phrophase II- nucleus disappears  Metaphase II- line up down middle  Anaphase II- split into two chromatids  Telephase II- split cells and develop into egg or sperm cells with 23 chromosomes

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chromosome Pairs  Normal cell has 46 chromosomes (23 pairs)  Pair 23 is sex chromosomes  XX- female  XY- male

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Chromosome Pairs  How do you get Down’s syndrome?  Called Trisamine 21  Pair 21 has three chromosomes instead of two

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Changes in Cell Growth  Hypertrophy- means a cell grows  Atrophy- means a cell shrinks  Hyperplasia- increase in number of cells  milk producing glands of women right after pregnancy

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Changes in Cell Growth  Body can lose ability to control cell reproduction- hyperplasia  mass of cells forms a neoplasm  benign  malignant- tumor cells can break away and travel through body

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cycle of Cell Life  As we get older cells function less efficiently  causes organs to lose function, skin to lose elasticity

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Disorder of Cellular Disease  Cystic Fibrosis  cloride ion pumps in plasma membrane missing  sweat is salty and mucus is thick  thick mucus blocks airway and digestive ducts  most die before adulthood  most common genetic disorder in Caucasians

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Disorder of Cellular Disease  Muscular Dystrophy  leaky membranes in muscle cells allow Ca to get into muscle  destroys the muscle cell  causes life threatening paralysis

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Diseases  Adult Onset Diabetes (Type II)  happens as a cellular response to obesity  reduces number of receptors for insulin  cells need insulin for energy  cells starve for energy even though glucose is right outside the cell

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Diseases  Sickle-Cell Anemia  genetic code is not passed on correctly  causes a mutation or a cell to change  red blood cells are not shaped correctly, are fragile, and can’t carry oxygen  most common genetic disorder among African Americans

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cellular Diseases  Tay-Sachs Disease  affects 1 in 1,000 births  predominant in Eastern European Jewish families  deficiency in one of the enzymes normally released by lysosomes in nerve cells in the brain  it normally digests lipid molecules in cytoplasm of cells  it doesn’t work so lipids build up in the cells  child usually dies between 2 and 4

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cancer  Over 2 million people a year die of cancer  2nd leading cause of death  1/2 of cancer is of the digestive tract  cells usually divide at the same rate cells die  cancer is uncontrolled cellular division

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cancer  Regulatory Factors  contact inhibition- when cells are packed so they touch each other, the division process is halted  on a sheet of glass normal cells will stop division when one full layer of cells formed  cancer cells divide uncontrollably

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings Cancer  Carcinogens- things that cause cancer  chemicals found in smoke  asbestos  certain dyes  radiation- ultraviolet and X-ray  leukemia is 10 times higher for radiologists as other physicians  food additives (sachhrine)  certain viruses  Early diagnosis best way to prevent death