Cell Structure, Function and Macromolecules

1. Cell Structure, Function and Macromolecules https://www.youtube.com/watch?v=gFuEo2ccTPA&feature=youtu.be

2. Levels of Organization • Organism • Organ System • Organ • Tissue • Cells • Atoms (Chemical)

3. Water and SolutionsA. Water in Living Things • 70% of the human body is water • Cells are filled with water and are surrounded by water.

4. A. Water in Living Things Properties of Water 1. Storage of heat: Water heats slowly and retains heat longer than many other substances. Example: Some organisms release excess heat by sweating (cool off) Feet have more sweat glands than any other part of the body (250,000) and can produce up to a pint of perspiration each day.

5. A. Water in Living Things Properties of Water 2. Cohesion: attraction between substances of the same kind • Cohesion is caused by the hydrogen bonds between water molecules • Surface Tension: caused by the attraction of water molecules http://www.youtube.com/watch?v=45yabrnryXk

6. A. Water in Living Things Properties of Water 3. Adhesion: attraction between different substances • Adhesion powers capillary action in which water molecules move water through a narrow tube such as a stem of a plant • The attraction of the water to the walls of the tube sucks the water up more strongly than gravity pulls it down.

7. Chemistry of Cell Macromolecules “Building Blocks” • Organic compounds contain Carbon atoms that are covalently bonded to other elements. • 4 classes of organic compounds found in living things: 1. carbohydrates 3. protein 2. lipids 4. nucleic acid

8. Carbohydrates -are made up of carbon, hydrogen, and oxygen atoms in 1:2:1 ratio • -are a key source of energy • -are found in most foods, especially fruits, vegetables, and grains

9. Monosaccharides • Monosaccharides -single sugars • Examples: glucose, fructose • Function: as a major source of energy in cells

10. Disaccharides • Disaccharides-double sugars (2 monosaccharides) • Examples: sucrose (made of glucose and fructose)

11. Polysaccharides • Polysaccharides-3 or more monosaccharides • Examples: starch • Function: storehouses of the energy stored in sugar • Starch-Stored by plants • Glycogen-made and stored by animals

12. Lipids • Lipids are nonpolar and are NOT soluble in water • Lipids include: fats, phospholipids, steroids, and waxes • Fats-Store energy • Phospholipids-Form cell membranes

13. Lipids *** Examine the difference between saturated and unsaturated fatty acids. * Saturated fats are solid at room temperature * Unsaturated fats are liquid at room temperature

14. Proteins • Large molecules formed by amino acids • AMINO ACIDS ARE THE BUILDING BLOCKS OF PROTEIN.

15. Proteins tend to fold into compact shapes

16. Functions of Proteins • Some proteins are enzymes and promote chemical reactions. • Collagen is a protein found in skin, ligaments, tendons, and bones. • Antibodies defend against infection. • Aid in muscle contraction • Hemoglobin is a protein found in blood that carries oxygen from the lungs to body tissues.

17. Nucleic Acids • Found in ALL cells • It is a long chain of smaller molecules called nucleotides (A, T, G, U and C) • 2 types of Nucleic acids

18. Nucleic Acids • DNA-deoxyribonucleic acid: made of 2 strands; stores hereditary information • RNA-ribonucleic acid; made of 1 strand ; manufactures proteins

19. Nucleic Acids ENERGY MOLECULE IS ATP. ATP is adenosine triphosphate; temporarily stores energy

21. Energy and Chemical Reactions • A. What is energy? Ability to move or change matter • Forms of energy include: light heat chemical mechanical electrical

22. Energy and Chemical Reactions

23. What is energy? In chemical reactions energy is stored or released. Reactants  Products NaCl  Na+ + Cl-

24. Activation Energy Activation Energy-energy needed to start a chemical reaction It is a “push” that starts a chemical reaction

25. Enzymes Enzymes-increase the speed of chemical reactions • Most enzymes are proteins. • Decrease the amount of energy needed to start a chemical reaction

26. Enzymes • Allow organisms to maintain homeostasis • Example: Carbonic anhydrase allows your body to eliminate CO2 efficiently • Draw the reaction CO2 + H2O H2 CO3 Carbonic anhydrase

27. Enzymes • Enzyme specificity-Enzymes act on only certain substances during a chemical reaction • These substances are called substrates

28. Enzymes Label active site, substrate, and enzyme

29. Enzymes What can effect enzyme activity? pH or temperature

30. 2. Acids and Bases • When hydrogen bonds in H2O break, a hydrogen (H+) ion and a hydroxide ion (OH-) forms Draw this: H2O  H+ + OH-

31. I. Looking at Cells • A. Scientists only became aware of cells after the invention of the microscope. • 1. 1665:Robert Hooke observed cork cells and called them “little boxes”. 1675:Anton van Leeuwenhoek used a microscope and observed pond water. He discovered many living creatures.

32. Cell Theory • A. Whose observations helped form the CELL THEORY? • 1838- MattiasSchleiden concluded that cells make up every part of the Plant. • 1839- Theodor Schwann concluded that animals are made up of cells. • 1858- Rudolph Virchow determined that cells only come from other cells.

33. 3 parts of the Cell Theory • 1. All living things are made up of one or more cells. • 2. Cells are the basic units of structure and function in organisms. • 3. All cells arise from existing cells.

34. CELL SIZE • Small cells function more efficiently than large cells. • How many cells are our bodies made up of? 100 trillion • The advantage of cells being smaller is that substances that enter or leave a cell must cross that cell’s surface; if the cell is small they can exchange substances more readily than large ones.

35. Relationship between Surface area and Volume

36. Common Features of Cells • Cell Membrane- outer boundary of cell • Function- regulates what enters and leaves the cell • Made up of- phospholipids and proteins • Cytoplasm- fills the cell; cell parts are suspended in this • Function- same as above • Made up of- water and salts

38. Cytoskeleton- a system of microscopic fibers • Function- provides framework, shape and support • Made up of- protein fibers

39. Ribosomes- proteins are made here • DNA- found in the nucleus • Function- provides instructions for making proteins, regulates cell activities • Made up of- nucleotides

40. Prokaryotes • Smallest and simplest cells. • Prokaryote- is a single-celled organism that LACKS a nucleus and other membrane bound organelles. • They were the only organisms on Earth for 2 billion years. They are very simple and small. The familiar prokaryotes that cause infection and cause food to spoil are commonly called Bacteria.

41. Characteristics of Prokaryotes • They can live everywhere. • They can cause infection in humans and grow and divide very rapidly. • Some do not need oxygen to survive. • Some can make their own food. • Prokaryotic cells have cytoplasm, cell wall, ribosomes, cell membrane & DNA (circular). Some have flagella for movement. • Some prokaryotic cell walls are surrounded by a capsule that enables the cell to cling to almost anything.

42. . Flagellum Capsule DNA Plasma Membrane Cell Wall Ribsomes

43. Eukaryotic Cells • A eukaryote is an organism whose cells have a nucleus. • Organelle-parts of the cell that carry out specific activities • Nucleus-internal compartment that holds DNA Function- controls cells activities

44. Cilia-short hair-like structures • Function-used for movement • Cytoskeleton- provides interior framework • Function- support and shape of the cell • Made up of- protein fibers: microfilaments, microtubules, intermediate fibers

45. CellMembrane • Cell Membrane- selective permeability (barrier) • Made up of- phospholipids and proteins

47. Membrane Proteins • Serve many roles including: as markers; as receptors to recognize and bind to substances; as enzymes; as transport proteins to move substances across the membrane

48. The Nucleus Contains Hereditary information- DNA & RNA RNA- made in nucleus; used to make proteins DNA- wound tightly into chromosomes Humans have 46 chromosomes. Garden peas have 14 chromosomes. Cell Organelles

49. Endoplasmic Reticulum-system of internal membranes • Function- moves proteins and other substances through the cell • Made up of- lipid bilayer & embedded proteins • Rough ER- contains ribosomes • Smooth ER- (lacks ribosomes)-makes lipids and breaks down toxins

50. C. Golgi Apparatus- flattened membrane- bound sac • Function- package and distribution center (UPS) • Made up of- proteins • D. Lysosomes- vesicles that bud off of Golgi Apparatus • Function-contains cell digestive enzymes • They are present in plant cells just fewer than are found in animal cells.