Cell Biology Chapter 3 PDF

THE CELLULAR LEVEL OF ORGANIZATION Chapter 3 Unless otherwise noted, the images and text used in this PowerPoint are from: Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J. E., Womble, M., & DeSaix, P. (2022). Chapter 9: Joints. In Anatomy and Phys...

THE CELLULAR LEVEL OF ORGANIZATION Chapter 3 Unless otherwise noted, the images and text used in this PowerPoint are from: Betts, J. G., Young, K. A., Wise, J. A., Johnson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J. E., Womble, M., & DeSaix, P. (2022). Chapter 9: Joints. In Anatomy and Physiology 2e. OpenStax. https://openstax.org/books/anatomy-and-physiology-2e/pages/9-introduction Chapter Objectives: After this chapter, you will be able to: ❑Describe the structure and function of the cell membrane, including its regulation of materials into and out of the cell ❑Describe the functions of the various cytoplasmic organelles ❑Explain the structure and contents of the nucleus, as well as the process of DNA replication ❑Explain the process by which a cell builds proteins using the DNA code ❑List the stages of the cell cycle in order, including the steps of cell division in somatic cells  Mitotic Cell Flourescence-stained Cell Undergoing Mitosis A lung cell from a newt, commonly studied for its similarity to human lung cells, is stained with fluorescent dyes. The green stain reveals mitotic spindles, red is the cell membrane and part of the cytoplasm, and the structures that appear light blue are chromosomes. This cell is in anaphase of mitosis. (credit: “Mortadelo2005”/Wikimedia Commons) The Cell Membrane SECTION 3.1 Phospholipid Structure Phospholipid Structure A phospholipid molecule consists of a polar phosphate “head,” which is hydrophilic and a non-polar lipid “tail,” which is hydrophobic. ▫ Unsaturated fatty acids result in kinks in the hydrophobic tails. ▫ Allows for the cell membrane to be selectively permeable  Phospholipid Bilayer Phospholipid Bilayer The phospholipid bilayer consists of two adjacent sheets of phospholipids, arranged tail to tail. The hydrophobic tails associate with one another, forming the interior of the membrane. The polar heads contact the fluid inside and outside of the cell.  Cell Membrane Cell Membrane The cell membrane of the cell is a phospholipid bilayer containing many different molecular components proteins cholesterol carbohydrate  Cell Membrane Cell Membrane - Proteins Channel proteins ○ allow large and charged molecules to pass through the membrane Integral proteins ○ anchors in the cell membrane Glycoproteins ○ cell recognition ○ cell signaling  Cell Membrane Cell Membrane - Cholesterol helps with cell fluidity cell stability cell flexibility  Cell Membrane Cell Membrane -Carbohydrates cell to cell recognition cell to cell signaling Glycocalyx ○ important in cell protection against pathogens ○ formed by: glycoproteins and glycolipids  Simple Diffusion Simple Diffusion non-polar substances oxygen and carbon dioxide lipids down their concentration gradient No helper or ATP needed  Facilitated Diffusion Facilitated Diffusion helper proteins such as channel proteins Large & charged molecule move through the channel down its concentration gradient No ATP Large & Charged examples Sons Aminos Glucose  Active Transport Sodium-Potassium Pump Needs a Helper Protein Powered by ATP, ○ sodium and potassium ions in opposite directions, each against its concentration gradient. In a single cycle of the pump, three sodium ions are pumped out of cell two potassium ions are pumped into cell. Active Transport  Endocytosis Forms of Endocytosis Endocytosis is a form of active transport in which a cell envelopes extracellular materials using its cell membrane. (a) In phagocytosis, which is relatively nonselective, the cell takes in a large particle. (b) In pinocytosis, the cell takes in small particles in fluid.. Endocytosis Exocytosis Exocytosis Exocytosis is much like endocytosis in reverse. Material destined for export is packaged into a vesicle inside the cell. ▫ The membrane of the vesicle fuses with the cell membrane ▫ The contents are released into the extracellular space.  Osmosis Osmosis Osmosis is the diffusion of water (movement) through a semipermeable membrane down its concentration gradient. Water follows solute through a semipermeable membrane Osmosis  Tonicity Concentration of Solutions A hypertonic solution has a solute concentration higher than another solution. An isotonic solution has a solute concentration equal to another solution. A hypotonic solution has a solute concentration lower than another solution. The Cytoplasm and Cellular Organelles SECTION 3.2  Prototypical Human Cell Prototypical Human Cell While this image is not indicative of any one particular human cell, it is a prototypical example of a cell containing the primary organelles and internal structures.  Cytosol/Cytoplasm Cytosol Fluid portion of cell excluding organelle Contributes to ○ cell structure ○ metabolic reactions ○ transport Cytoplasm consist of cytoskeleton, cytoplasm and organelle  Cytoskeleton The Three Components of the Cytoskeleton The cytoskeleton consists microtubules, microfilaments intermediate filaments. The cytoskeleton plays an important role in maintaining: cell shape and structure, promoting cellular movement aiding cell division Cytoskeleton  Endoplasmic Reticulum Endoplasmic Reticulum (ER) is a winding network of thin membranous sacs found in close association with the cell nucleus. Rough ER makes protein with ribosomes Smooth ER makes lipids no ribosomes EM × 110,510. (Micrographs provided by the Regents of University of Michigan Medical School © 2012)  Golgi Apparatus Golgi Apparatus The Golgi apparatus manipulates products from the rough ER, and also produces new organelles called lysosomes. Proteins and other products of the ER are sent to the Golgi apparatus, which organizes, modifies, packages, and tags them. Some of these products are transported to other areas of the cell Some are exported from the cell through exocytosis.  Mitochondrion Mitochondrion POWER HOUSE OF CELL The mitochondria are the energy-conversion factories of the cell Bilayer membrane. Along the inner membrane are various molecules that work together to produce ATP An electron micrograph of mitochondria. EM × 236,000.(Micrograph provided by the Regents of University of Michigan Medical School © 2012)  Membrane bound Structures Peroxisome contain an abundance of enzymes for detoxifying harmful substances and lipid metabolism. Lysosome break down waste products Vacuoles Store nutrients and waste for later use or to dispose of  Non - Membrane bound Structures Ribosome made in the nucleus Protein synthesis (Translation) works with mRNA and tRNA Can be found in the RER or in cytosol The Nucleus and DNA Replication SECTION 3.3  Nucleus The Nucleus is the control center of the cell. contains the genetic material determines the entire structure and function of that cell..  Nucleus Nuclear pores allows ribosomes and mRNA out of nucleus Nuclear envelope protects genetic material Chromatin stores genetic material DNA & proteins Nucleolus site of ribosome production Nucleic acids Includes DNA (genetic blueprint) and RNA (key to protein synthesis).  Nucleus Nucleic acids RNA (key to protein synthesis) mRNA ○ instructions for protein assembly with ribosome tRNA ○ transfers amino acids to make proteins rRNA ○ helps form the ribosome.  Transcription Transcription: from DNA to mRNA In the first of the two stages of making protein from DNA, a gene on the DNA molecule is transcribed into a complementary mRNA molecule. Translation Translation from RNA to Protein During translation, the mRNA transcript is “read” by a functional complex consisting of the ribosome and tRNA molecules. tRNAs bring the appropriate amino acids in sequence to the growing polypeptide chain Cell Growth and Division SECTION 3.5  The Cell Cycle Cell Cycle The two major phases of the cell cycle Mitosis (cell division) this is for growth and repair diploid cell 23 pairs of chromosomes (46) Interphase when the cell grows and performs all of its normal functions. Anaerobic vs Aerobic Respiration Depends on presence or absence of oxygen Anaerobic respiration converts glucose into two lactate molecules in the absence of oxygen Aerobic respiration converts glucose into two pyruvates in the presence of oxygen Erythrocytes that lack mitochondria utilize anaerobic as well  Glycolysis Two ATPs are consumed in the energy-consuming phase of glycolysis, to transfer two phosphates to the glucose molecule Occurs in the Cytosol Anaerobic Respiration Produce produce four ATPs (NET: of 2) 2 pyruvate if not used then turns into lactic acid 2 NADH Glycolysis and Kreb’s Cycle (6:27)  Kreb’s (Citric Acid) Cycle Each pyruvate is oxidized into a two-carbon acetyl-CoA molecule Each acetyl-CoA is processed through the cycle and produces several high energy molecules 3 NADH (6) 1 FADH2 (2) 2 ATP (4) Since the cycle starts with two pyruvates, this process occurs twice per single glucose molecule Kreb’s cycle overview (3:19)  Oxidative Phosphorylation Includes two different processes The electron transport chain is a series of electron carriers and ion pumps + that are used to pump H ions out of the inner mitochondrial matrix as electrons are delivered by electron carriers Oxygen is a common final electron acceptor ATP synthase uses the H+ concentration gradient to fuel synthesis of ATP Electron Transport Chain (17:15)  Key Takeaway for ETC NADH & FADH2 donate ○ electrons & protons Electrons power the complexes to move protons to the inner membrane. (against the gradient) Protons are need to power the ATP synthase ○ produces ATP Oxygen is the final electron acceptor The ETC produces 34 ATP Total ATP from 1 glucose molecule - 36 ATP  Carbohydrate Metabolism Summary Involves glycolysis, the Kreb’s cycle, and the electron transport system Total ATP produces can vary with efficiency of system