Chapter 3

1. Chapter 3 By: Bailey

2. What is cell theory?

3. Cell Theory • Cells are building blocks for plants and animals • Cells are produced by division for preexisting cells • Cells are the smallest object that perform physiological functions • Each cell maintains homeostasis at cellular level • Homeostasis at the tissue, organ, system, and individual levels reflects the combined and coordinated actions of many cells • *Homeostasis- the maintenance of a relatively constant internal environment

4. Compare fluid contents of cell with the extracellular fluid

5. Fluid Content Cytosol Extracellular • High concentration of potassium • Relatively high concentrations of dissolved proteins (enzymes that regulate metabolic operations) • Contains dissolved nutrients, ions, soluble and insoluble proteins and waste products • Contains small quantities of carbohydrate and large reserves of amino acids and lipids • High concentration of sodium • All body fluid not within the cell • Plasma and interstitial fluid are included in this

6. Cell membrane

7. Cell membrane Structure Importance • Composed of • Phospholipids • Proteins • Glycolipids • Cholesterol • * Cytosol is what mostly makes up the cell. Surrounding that is the Phospholipid bilayer, and within that layer are the proteins and channels • Separates the inside of the cell from the surrounding extracellular fluid • Controls the entry of ions and nutrients, and eliminates waste and the release of secretory products • Let’s the cell respond and recognize to molecules in its environmental • Gives tissues a stable structure

8. Cell and their environment

9. Interaction with Environment • A cell needs to maintain homeostasis • It does this through the cell membrane • Taking in nutrients and obtaining water balance and giving off waste • These all are from the environment that need to be taken in or let into the environment from the cell

10. Structure and function

11. organelles • Cytosol- distributes materials by diffusion • Cell Membrane- isolation, protection, sensitive, organization

12. Organelles Nonmembranous Organelles Membranous Organelles • Cytoskeleton • Microtubules • Microfilaments • Microvilli • Cilia • Centrioles • Ribosomes • Nucleus • Endoplasmic reticulum • Rough ER • Smooth ER • Golgi Apparatus • Lysosomes • Peroxisomes

13. Nonmembranous • Cilia- movement of materials over surface • Centrioles- movement of chromosomes during cell division • Ribosomes- protein synthesis • Cytoskeleton- strength, movement of cellular structures and material • Microtubules- gives strength to the cell • Microfiliments-slender protein strand • Microvilli-absorption of extracellular fluid

14. Membranous • Smooth ER- lipid and carbohydrate synthesis • Golgi apparatus-storage, alteration and package of secretory product and lysosomes • Lysosomes- intercellular removal of damaged organelles or of pathogens • Peroxisomes- neutralization of toxic compounds • Mitochondria- protein synthesis • Nucleus- control of metabolism; stores and processes genetic info. • Nucleolus- site of RNA synthesis • Endoplasmic Reticulum- synthesis of secretory products; intracellular storage and transport • Rough ER- secretory protein synthesis

15. Energy within Cells

16. Mitochondria Mitochondria How it preforms that… • Mitochondria is the power house of the cell, it makes and stores the “power” so the cell can function properly • * Metabolic enzymes - Protein-based substances that promote change in bodily cells… • The organelle has a double membrane; the first surrounds the entire cell, the second surrounds the inner which has many folds called cristae • Cristae increases the surface area exposed to the fluid contents, matrix • Matrix contains metabolic enzymes that perform the reactions that provide energy for cellular function

17. Nucleus as control center

18. Nucleus • The nucleus is surrounded by the nuclear envelope which separates it from the cytosol • Within the nuclear envelope are perinuclearspace • These allow the nucleus to receive information about conditions and activities in the cytosol

19. Nucleoplasm • The nucleoplasm contains ions, enzymes, RNA and DNA nucleotides, proteins, small amounts of RNA and DNA • These DNA strands form a chromosome • These are then “read” by the nucleus controls by the process of “regulation of protein synthesis” • What is read from the chromosome, the nucleus then tells the cell what needs done and what to do

20. Life Cycle

21. Life Cycle • Life cycle- Go Phase, G1 Phase, S Phase, G2 Phase, Gm Phase, Mitosis

22. Interphase • Go Phase- the cell has normal functions (indefinite time) • G1 Phase- the cell grows, duplicates its organelles, and preforms protein synthesis (8 or more hours) • S Phase- the cell’s DNA is replicated and synthesis’s its histones (6-8 hours) • G2 Phase- the cell undergoes protein synthesis’s (2-5 hours) • Gm Phase- where the cell undergoes mitosis

23. Mitosis • Prophase (stage 1)- the nuclear envelope disappears • Metaphase (stage 2)- chromatids move through metaphase plate; microtubules of the spindle apparatuses attaches to each centromere • Anaphase (stage 3)- the chromatid pairs separate and the daughter chromosomes move toward the opposite ends to the cell • Teleophase (stage 4)- the nuclear membranes form, the nuclei enlarge, chromosomes gradually uncoil; once the chromosomes disappear, nucleoli reappear and the nuclei resemble those of the interphase cell

24. Importance trans -membrane Potential

25. Trans-membrane Potential • It measures the millivolts across the cell membrane for potential difference that could result from uneven distribution of the positive and negative ions across a cell membrane • A membrane enzyme called the sodium-potassium pump actively transports ions to compensate for the sodium and potassium leaks • This pump uses the energy of ATP to move sodium and potassium against their electrochemical gradients • The pump compensates for the sodium and potassium leaks, keeping the resting membrane potential at -70 millivolts

26. How cells attach

27. Methods of Attachment • Gap Junction- two cells are held together by an interlocking of membrane proteins, the result is a narrow passage way that lets small molecules and ions pass from cell to cell • Tight Junction- partial fusion of the lipid portions of the two cell membranes, providing mechanical strength, but blocking the water or solutes between cells • Intermediate Junction- the opposing cell membrane, while maintaining distinct, are held together by a thick layer of proteoglycans • Desmosomes- the opposing cell membranes reinforced by a network of intermediate filaments that lock the two together , a dense concentration of filament beneath the cell membrane at a desmosomes anchor it to the cytoskeleton • Junction Complex- when all types of junctions including desmosomes are together in one location

28. Vocabulary

29. Vocab. • Cytology- the study of the structure and function of cells • Transmission electron microscopy- show fine structures of cell membranes and intracellular structures • Scanning electron microscopy- where electrons bounce off exposed surfaces, creates 3D perspective • Extracellular fluid- a watery medium that is on the outside of cells • Cell membrane- outer boundary of the cell • Plasma membrane- another term for cell membrane • Phospholipid bilayer- a cell membrane • Peripheral proteins- attached to the inner membrane surface • Integral proteins- embedded in the membrane • Channels- formed by integral proteins the let water molecules, and other objects pass through it • Cytoplasm- A general term for the material inside of the cell

30. Vocab. • Intermediate filaments- provides strength, support, and transports materials within the cytoplasm • Neurofilaments- found in nerve cells and provide structure and support • Thick Filaments- massive strand composed of myosin protein subunits • Microtubules- hollow tubes built from the globular proteins • Tubulin- globular protein • Microvilli- small finger-shaped projections of the cell membrane • Centrioles- is a cylindrical structure composed of short microtubules • Centrosome- cytoplasm surrounding • Cilia- contain nine pairs of microtubules surround a central pair

31. Vocab. • Cytoplasm- A general term for the material inside of the cell • Cytosol- or intracellular fluid- dissolved nutrients, ions, soluble, and insoluble proteins and waste products. • Organelles- structures that perform specific functions within the cell • Inclusions- masses of insoluble materials • Non-membranous organelles- in contact with cytosol • Membranous Organelles- surrounded by lipid membranes that isolates them from the cytosol • Cytoskeleton- an internal protein framework the gives the cytoplasm strength and flexibility • Microfilaments- slender proteins strands composed of the protein actin • Actin- a protein found in microfilaments • Myosin- a protein

32. Vocab. • Basal Body- an anchored compact for cilia • Flagella- moves cells through the surrounding fluids • Ribosomes- small, dense structure that cannot be seen; they manufacture proteins • Free ribosome- one type of ribosome where its proteins scatter throughout the cytoplasm • Fixed ribosome- attached to the endoplasmic reticulum, its proteins enter here • Mitochondria- small organelle that have a double membrane; makes energy for the cell • Cristae- second inner membrane that contains numerous folds • Matrix- fluid contents of mitochondrion • Respiratory enzyme- produces most of the ATP generated from the mitochondrion • Nucleus- the control center for the cell • Nuclear envelope- surrounds the nucleus and separates it from the cytosol • Perinuclear space- a narrow passage within the nuclear envelope

33. Vocab. • Nuclear pores- large pores that permit the movement of ions and small molecules,but too small for DNA • Nucleoplasm- fluid contents of the nucleus • Chromosomes- contain DNA strands • Histones- proteins that bind to DNA strands • Nucleosome- a structure that forms when DNA strands wind around histones • Chromatin- made when chromosomes tangle fine filaments • Endoplasmic reticulum- a network of intracellular membranes • Cisternae- formed by the endoplasmic reticulum; reservoir for water • Rough reticulum- where newly made synthetic proteins undergo chemical modification • Smooth reticulum- synthesis of lipids and carbohydrates

34. Vocab. • Golgi apparatus- synthesis and packing, renewal or modification of the cell membrane • Transfer vesicles- how material moves from saccule to saccule • Secretory vesicles- vesicles that contain secretion that will be discharged • Lysosomes- vesicles filled with digestive enzymes; defense against disease • Endocytosis- the process of lysosomes in greater detail • Peroxisomes- smaller then lysosomes; absorb and neutralize toxins • Gated- regulate the passage of materials that travel through channels • Glycocalyx- protects cell membrane; function as receptors; keeps immune system from attacking body • Permeability- objects can pass through it • Impermeability- objects cannot pass through it • Freely permeable- object can pass through without any trouble is said to be • Selectively permeable- permits the passage of some materials

35. Vocab. • Diffusion- net movement of material from an area where it’s concentrated from high to low • Concentration gradient- the difference between low and high concentration • Osmosis- the response to the difference in diffusion • Osmotic pressure- force of water movement • Hydrostatic pressure- when pressure is can prevent the entry of molecules • Osmotic concentration/osmolality- total solute concentration in a solution • Tonicity- used when describing osmotic concentration • Isotonic- same solute concentration low and high • Hypotonic- solution has a lower then the cytoplasm • Hemolysis- when a cell burst or explodes • Hypertonic-when concentration is higher than the cytoplasm