Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Memmler’s The Human Body in Health and Disease 11 th edition Chapter 3 Cells and Their Functions

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Role of Cells Cytology is the study of cells Basic unit of all life Have all characteristics of life Can live independently of other cells

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins MicroscopesMicroscopes Single lens Compound light Transmission electron Scanning electron

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-1: The cell is the basic unit of life. What characteristics of life does it show? Checkpoint 3-2: Name three types of microscopes.

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cell Structure All cells share certain characteristics.

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins A generalized animal cell, sectional view. ZOOMING IN What is attached to the ER to make it look rough? What is the liquid part of the cytoplasm called?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Plasma Membrane Encloses cell contents Participates in cellular activities Bilayer structure –Phospholipids –Cholesterol –Proteins

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The plasma membrane. ZOOMING IN How many layers make up the main substance of the plasma membrane?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-3: The outer limit of the cell is a complex membrane. What is the main substance of this membrane and what are the three types of materials found within the membrane?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Nucleus Largest organelle in a cell Chromosomes Nucleolus

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-4: What are cell organelles? Checkpoint 3-5: Why is the nucleus called the control center of the cell?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: What is the largest organelle in the cell? a. a mitocondrion b. a lysosome c. the nucleus

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: c. the nucleus

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Cytoplasm Material that fills the cell from the nuclear membrane to the plasma membrane Endoplasmic reticulum Ribosomes Mitochondria Golgi apparatus Lysosomes Peroxisomes Vesicles Centrioles

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Surface Organelles Structures projecting from the cell surface used for motion Cilia Flagellum

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cellular Diversity Individual cells vary widely Size Shape Function

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: Which organelle is known as the “powerhouse” of the cell? a. the nucleus b. the mitochondrion c. the nucleolus

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. the mitochondrion

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-6: What are the two types of organelles used for movement, and what do they look like?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Protein Synthesis Cellular substances that direct the production of proteins Chromosomes –Genes

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Nucleic Acids—DNA and RNA DNA and RNA have similar structures Four nucleotides –Adenine (A) –Guanine (G) –Cytosine (C) –Thymine (T) or uracil (U) Sugar –Ribose or deoxyribose Phosphate Nitrogen base

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins DNA DNA in a cell occurs mainly in chromosomes Genes are subdivisions of chromosome Genes code for the building of amino acids

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Structure of DNA. ZOOMING IN Two of the DNA nucleotides (A and G) are larger in size than the other two (T and C). How do the nucleotides pair up with regard to size?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-7: What are the building blocks of nucleic acids? Checkpoint 3-8: What category of compounds does DNA code for in the cell?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The Role of RNA Protein synthesis Transcription –Messenger RNA (mRNA) Translation –Transfer RNA (tRNA) –Ribosomal RNA (rRNA)

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Transcription.

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Translation.

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-9: What three types of RNA are active in protein synthesis?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: If the nucleotides on a DNA strand read CGAT, what will its corresponding RNA strand read? a. TAGC b. GCUA c. GCTA

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. GCUA

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cell Division Meiosis –Sex cells Mitosis –Somatic cells

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-10: What must happen to the DNA in a cell before mitosis can occur? During what stage in the life of a cell does this occur?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Stages of Mitosis Prophase Metaphase Anaphase Telophase

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins The stages of mitosis. ZOOMING IN If the original cell shown has 46 chromosomes, how many chromosomes will each new daughter cell have?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-11: What are the four stages of mitosis?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Movement of Substances Across the Plasma Membrane Travel across the membrane is based on several factors: Molecular size Solubility Electrical charge

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Movement That Does Not Require Cellular Energy Passive transport Diffusion Osmosis Filtration Facilitated diffusion

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Movement That Requires Cellular Energy Active transport Bulk transport or vesicular transport –Endocytosis Phagocytosis Pinocytosis –Exocytosis

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: In which type of active transport does the plasma membrane surround and engulf droplets of fluid? a. pinocytosis b. endocytosis c. phagocytosis

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: a. pinocytosis

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-12: Substances are constantly moving into and out of cells through the plasma membrane. What types of movement do not require cellular energy and what types of movement do require cellular energy?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins How Osmosis Affects Cells Fluid solutions Isotonic –Cells not affected Hypotonic –Cells swell and may burst; in red cells = hemolysis Hypertonic –Cells lose water and shrink; crenation

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Checkpoint 3-13: The concentration of fluids in and around the cell is important in homeostasis. What term describes a fluid that is the same concentration as the fluid within the cell (intracellular fluid)? What type of fluid is less concentrated? More concentrated?

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: Cells placed in a hypertonic solution undergo what change? a. crenation b. rupture c. apoptosis

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: a. crenation

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cell Aging As cells multiply, changes occur that may lead to their damage or death Free radical injury Enzyme injury Gene alteration or mutation Slowing cell activity Apoptosis

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cells and Cancer Certain mutations may cause changes in cells Uncontrolled reproduction of cells Cells spread (metastasize), producing cancer Cancer cells form tumors, crowding out normal cells

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question: When cancer cells multiply and spread, they are said to do what? a. mutate b. metastasize c. lyse

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer: b. metastasize

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Cancer Risk Factors Certain forces increase the chances of developing cancer Heredity Chemicals Ionizing radiation Physical irritation Diet Viruses

Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins End of Presentation