Human Anatomy & Physiology

Transcription

1 PowerPoint Lecture Slides prepared by Barbara Heard, Atlantic Cape Community College Ninth Edition Human Anatomy & Physiology C H A P T E R 3 Annie Leibovitz/Contact Press Images 2013 Pearson Education, Inc.

2 An Introduction to Cells Sex Cells (Germ Cells) Reproductive cells sperm, oocyte Somatic Cells Soma = body All body cells except sex cells

3 Plasma Membrane Cell environment? what s outside these cell? Extracellular Fluid watery medium that surrounds a cell What prevents the extracellular fluid from entering cell? Plasma membrane

4 What s making this up? EXTRACELLULAR FLUID Cytoplasm Lipids and Proteins

5 Plasma Membrane Outside cell Hydrophilic Hydrophobic Hydrophilic Inside cell

6 Two kinds of proteins EXTRACELLULAR FLUID Integral CYTOPLASM Peripheral proteins

7 Diffusion and Osmosis Plasma membrane is selectively permeable selective based on: Size Electrical charge Molecular shape Lipid solubility

8 Diffusion and Osmosis Transport through a plasma membrane can be: Active : requiring energy as ATP Passive : no energy required four types of transport: Diffusion (passive) Carrier-mediated transport (passive or active) Vesicular transport (active)

9 Diffusion and Osmosis Passive transport think: molecules [high] [low] Concentration gradient More solute in one part of a solvent than another Following of a concentration gradient is Diffusion

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11 Diffusion and Osmosis Diffusion can be simple pass through plasma membrane Lipid-soluble Dissolved gases

12 Diffusion and Osmosis Diffusion can be Channel-mediated diffusion Need a port/tunnel Water-soluble compounds and ions Interaction with the channel leak channels

13 EXTRACELLULAR FLUID Lipid-soluble molecules Channel protein Large molecules Small water-soluble molecules and ions diffuse through membrane channels CYTOPLASM

14 Diffusion and Osmosis Osmosis: A Special Case of Diffusion Osmosis diffusion of water across the cell membrane depends on the amount of solute concentration in cell three types of solutions:

15 Diffusion and Osmosis Osmolarity and Tonicity Isotonic (iso- = same, tonos = tension) No flow of water in or out of a cell Hypotonic (hypo- = below) Has less solutes and loses water through osmosis Hypertonic (hyper- = above) Has more solutes and gains water by osmosis

16 Water molecules Solute molecules SEM of normal RBC in an isotonic solution

17 SEM of RBC in a hypotonic solution

18 SEM of crenated RBCs in a hypertonic solution

19 Carriers and Vesicles Carrier-Mediated Transport Both passive and active Facilitated Diffusion Passive too large to fit through channel proteins two steps involved

20 Figure 3-18 Facilitated Diffusion Receptor Bound Shape Change transport

21 Carriers and Vesicles Carrier-Mediated Transport Active Transport (Primary or Secondary) Active transport proteins Move substrates against concentration gradient Require energy, such as ATP Ion pumps

22 Carriers and Vesicles Carrier-Mediated Transport Primary Active Transport Sodium potassium exchange pump Active transport

23 EXTRACELLULAR FLUID Primary Active Transport Sodiumpotassium exchange pump CYTOPLASM

24 Carriers and Vesicles Carrier-Mediated Transport Secondary Active Transport point: something else tags along Na + concentration gradient drives glucose transport ATP energy pumps Na + back out

25 Secondary Active Transport Glucose molecule Sodium ion (Na + ) pump CYTOPLASM

26 Carriers and Vesicles Vesicular Transport (Bulk Transport) Materials move into or out of cell in vesicles Into (endocytosis) Out of (exocytosis) Endocytosis is active transport using ATP 3 types

27 Carriers and Vesicles Endocytosis Receptor-mediated endocytosis Receptors bind target molecules Coated vesicle carries materials into cell

28 Carriers and Vesicles Endocytosis Pinocytosis Small particles ingested - drank by the cell Phagocytosis Pseudopodia (pseudo- = false, pod- = foot) Engulf large objects in phagosomes Exocytosis (exo- = outside) Granules or droplets are released from the cell

29 Bloodstream Plasma membrane Cytoplasm Pinosome formation Surrounding tissues Pinosome fusion and exocytosis Pinocytosis Color enhanced TEM 20,000

30 Plasma Membrane What s going on inside the cell? liquid bits (cell machinery)

31 Organelles and the Cytoplasm Cytoplasm All materials inside the cell and outside the nucleus Cytosol (intracellular fluid) Nutrients, ions, proteins, and waste products Organelles little organs with specific functions some have no membrane some have a membrane Know Fig. 3-2

32 Organelles and the Cytoplasm Nonmembranous Organelles Six types 1. Cytoskeleton 2. Microvilli 3. Centrioles 4. Cilia 5. Ribosomes 6. Proteasomes

33 Organelles and the Cytoplasm Membranous Organelles Six types of membranous organelles 1. Endoplasmic reticulum (ER) 2. Golgi apparatus 3. Lysosomes 4. Peroxisomes 5. Mitochondria 6. Nucleus

34 Organelles and the Cytoplasm Mitochondria Mitochondrion takes chemical energy from food Produces energy molecule ATP

35 Nucleotides to store energy ATP = energy currency molecule Adenine + phosphates Adenine Phosphorilation: addition of high energy phosphates groups Ribose Phosphate Phosphate Phosphate Adenosine High-energy bonds Adenosine diphosphate (ADP) Adenosine triphosphate (ATP) Adenine

36 Inner membrane Outer membrane Matrix Cristae Mitochondrion TEM 46,332

37 CYTOPLASM Glucose Glycolysis Anaerobic Pyruvate Citric Acid Cycle ETC cristae MATRIX MITOCHONDRION Aerobic END RESULT : +/- 30 ATP per Glucose molecule

38 Cell s Control Center Chromatin Nucleolus Nuclear envelope Nuclear pore Important nuclear structures are shown here. Nucleus TEM 4800

39 Nucleus Contents of the Nucleus Cell prepared for division Visible chromosome Nondividing cell whole point of DNA? Chromatin in nucleus Histones

40 Protein Synthesis Two processes are involved in protein synthesis Transcription DNA mrna Translation mrna AA polypeptide

41 Protein Synthesis So, how does transcription happen?

42 DNA Template strand Coding strand RNA polymerase Codon 1 mrna strand Promoter Codon 2 Gene Triplet 1 Triplet 2 Triplet 3 1 Complementary triplets Codon 1 RNA nucleotide Codon 3 Codon 4 (stop codon) Triplet 4 4 KEY Adenine Guanine Cytosine Uracil (RNA) Thymine (DNA)

43 Protein Synthesis After Transcription Translation How does translation work?

44 NUCLEUS mrna Amino acid KEY Adenine Guanine Small ribosomal subunit trna Anticodon trna binding sites Cytosine Uracil Start codon mrna strand

45 Large ribosomal subunit

46 Stop codon

47 Peptide bond

48 Small ribosomal subunit Completed polypeptide Large ribosomal subunit

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