Cells

1. Cells

2. Student Outcomes • Understand the structure of atoms • Types of molecular bonds • Compounds • Properties of water • Ions • Acids/bases • Macromolecules • Describe the physiology of cells and cell membranes including membrane transport processes.

3. BACKGROUND • Chemistry

4. Levels of Structural Organization • Chemical – atoms combined to form molecules • Cellular–cells are made of molecules • Tissue – consists of similar types of cells • Organ – made up of different types of tissues • Organ system – consists of different organs that work closely together • Organismal – made up of the organ systems

5. 2 Smooth muscle cell Cellular level Cells are made up of molecules Molecules Atoms 1 Chemical level Atoms combine to form molecules Blood vessel (organ) Smooth muscle tissue 3 Tissue level Tissues consist of similar types of cells Cardiovascular system Epithelial tissue Smooth muscle tissue Connective tissue Heart Blood vessels 6 Organismal level The human organism is made up of many organ systems 4 Organ level Organs are made up of different types of tissues 5 Organ system level Organ systems consist of different organs that work together closely

6. Composition of the body: • Major elements: (96%) – Carbon (C ), Oxygen (O), Nitrogen (N), Hydrogen (H) • Lesser elements make up 3.9% of the body and include: – Calcium (Ca), Phosphorus (P), Potassium (K), Sulfur (S), Sodium (Na), Chlorine (Cl), Magnesium (Mg), Iodine (I), and Iron (Fe) • Trace elements make up less than 0.01 % of the body – They are required in minute amounts, and are found as part of enzymes • Elements combine to make molecules –H2O –CO2– O2

7. Chemistry Overview • Atoms • Nucleus with protons, neutrons, electrons • Ions • Bonding • Covalent bonds • Ionic bonds • Hydrogen bonds

8. Atoms • All matter is composed of elements, which cannot be broken down into simpler substances by ordinary methods. • Carbon, oxygen, hydrogen, and nitrogen make up about 96% of our body weight. • Each element is composed of atoms. • Atoms are a cluster of particles called protons, neutrons, and electrons. • The protons (+ charge) and neutrons (no charge) make up the center of the atom (its nucleus), and the electrons ( - charge) circle the nucleus of the atom in an orbital motion.

9. Elements • What makes one element different from another element is the number of electrons orbiting the nucleus of the atom. • Hydrogen has only one electron. • Oxygen has eight electrons. • The first two electrons of any atom always orbit at the closest distance to the nucleus, called the first valence shell. • The next largest shell around the nucleus can hold up to 8 electrons. If there are more electrons than that, they will orbit in the next shell, and so on.

10. Oxygen • Since Oxygen has 8 electrons, the first two stay in the inner orbital. The next 6 will stay in the next largest orbital. Since that orbital can hold 8, oxygen always seeks two more electrons to complete its outermost shell (all the other elements do this also). • Therefore, oxygen frequently pairs with itself and shares its electrons. The first oxygen uses two electrons from the other oxygen, while the other does likewise. Thus, they often travel in pairs, called O2.

11. Outermost electron shell (can hold 8 electrons) First electron shell (can hold 2 electrons) Electron Nitrogen (N) Atomic number = 7 Oxygen (O) Atomic number = 8 Hydrogen (H) Atomic number = 1 Carbon (C) Atomic number = 6 0 An element is an atom with a certain number of electrons (electrical charges) circling around it in an orbit.

12. What would happen if oxygen were to disappear worldwide for five seconds?

13. What would happen if oxygen were to disappear worldwide for five seconds? • Everyone at the beach would get sunburns. Ozone is molecular oxygen, and blocks the majority of UV light. Without it we are toast. • The day-time sky would get darker. With less particles in the atmosphere to scatter blue light, the sky would get a bit less blue and a bit more black. • Every internal combustion engine would stall. This means that every airplane taking off from a runway would likely crash to the ground, while planes in flight could glide for some time. • All pieces of untreated metal would instantly spot weld to each other. The reason metals don't weld on contact is they are coated in a layer of oxidation. In vacuum conditions, metal welds without any intermediate liquid phase. 

14. What would happen if oxygen were to disappear worldwide for five seconds? • Everyone's inner ear would explode. As mentioned, we would lose about 21% of the air pressure in an instant, equivalent to being teleported to the top of the high Andes (~2000m elevation). • Every building made out of concrete would turn to dust. Oxygen is an important binder in concrete structures (really, the CO2 is), and without it the compounds do not hold their rigidity.  • Every living cell would explode in a haze of hydrogen gas. Water is one third oxygen, without it the hydrogen turns into gaseous state and expands in volume.  • The Oceans would evaporate and bleed into space. As oxygen disappears from the oceans' water, the hydrogen component becomes an unbound free gas. Hydrogen gas, being the lightest, will rise to the upper troposphere and slowly bleed into space through Atmospheric escape.

15. What would happen if oxygen were to disappear worldwide for five seconds? • Everything above ground would immediately go into free fall. As oxygen makes up about ~45% of the Earth's crust and mantle, there is suddenly a lot less "stuff" beneath your feet to hold everything up. • There will be a huge Explosion due to the oxidation of all the oceans that have been converted to Hydrogen

16. Water • Since hydrogen has one electron, it needs one more to complete its outermost orbital. • It frequently binds with another hydrogen and one oxygen (H2O). Both hydrogens donate their electron to the one oxygen so the oxygen can have its outer electron orbital filled, and both hydrogens have their outer orbitals filled also.

17. Water • The bond form by hydrogen and water is a covalent bond, which is strong. • The water molecule then has a positive charge on one end and a negative charge on the other end. • The positive charge on one water molecule will be attracted to the negative charge on a different water molecule. This bond is a hydrogen bond, which is weak and easily broken. • Water Molecules Video • http://www.youtube.com/watch?v=sBZfPmIcS-E

19. (–) (–) O H H (+) (+) 0 Water Molecule

20. Hydrogen bond Ice Hydrogen bonds are stable Liquid water Hydrogen bondsconstantly break and re-form 0 Ice is less dense than liquid water • Hydrogen bonds hold molecules in ice farther apart than in liquid water

21. Types of Bonds • Covalent Bond video • Ion Bond video

22. What have you learned so far today?How can you apply this information to patient health care?

23. Compounds • Two or more elements • Hydrogen (H) and Oxygen (O) = H2O • Sodium (Na) and Chlorine (Cl) = NaCl • Demonstrates new properties with a higher level of structural organization • Carbon, hydrogen, oxygen, and nitrogen form most of the compounds in living organisms

24. Sodium Chloride Chlorine Sodium 0 Elements can combine to form compounds

25. Sodium and chloride ions • Bond to form sodium chloride, common table salt

26. Water is the solvent of life • Solution: a liquid consisting of a uniform mixture of two or more substances. • Solvent: the dissolving agent • Solute: the substance that is dissolved

27. Ions • An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. • Sodium = Na+ • Potassium = K+ • Chloride = Cl-

28. Types of Chemical Bonds • Covalent bond: two atoms sharing elections; stable. • Hydrogen bond: when hydrogen, having a positive charge (it lacks an electron) is attracted to an atom with a negative charge. In this case, the electrons are not shared; the bond is electromagnetic. These bonds are weak and unstable. This type of bond pulls a protein into its 3-Dimensional shape. Acids and heat can break the bond, causing the protein to straighten out. Hydrogen bonds also cause curly hair. A hot iron can break the bonds and the hair will straighten or curl in the position it cools in. Getting the hair wet will reform the hydrogen bond and the hair goes back to its original position. • Ionic bond: Formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation (+), which is usually a metal, and an anion (-), which is usually a nonmetal.

29. Bonds Covalent Bond Hydrogen Bond

30. Ionic Bonds Sodium and fluorine bonding ionically to form sodium fluoride. Sodium loses its outer electron to give it a stable electron configuration, and this electron enters the fluorine atom exothermically. The oppositely charged ions are then attracted to each other. http://en.wikipedia.org/wiki/File:NaF.gif

31. Acids and Bases • Some water molecules break apart into ions. • Hydrogen ions (H+) • Hydroxide ions (OH-) • Acid: excess hydrogen ions (H+) • hydrochloric acid in your stomach • Base: excess hydroxide ions (OH-) • Ammonia is a base

32. pH scale 0 1 H+ H+ H+ OH– H+ 2 Lemon juice, gastric juice OH– H+ H+ H+ H+ Increasingly ACIDIC(Higher concentration of H+) 3 Grapefruit juice, soft drink Acidic solution 4 Tomato juice 5 6 Human urine OH– OH– NEUTRAL[H+]=[OH–] OH– 7 Pure waterHuman blood H+ H+ OH– OH– H+ H+ 8 H+ Seawater Neutral solution 9 10 Increasingly BASIC(Lower concentration of H+) Milk of magnesia 11 Household ammonia OH– OH– 12 OH– OH– H+ Household bleach OH– OH– 13 OH– H+ Oven cleaner 14 Basic solution pH scale • Neutral: pH = 7 • Acid: pH < 7 • Base: pH > 7

33. How does this material relate to health care? What health problems might a patient experience that has something to do with what we have covered so far today?

34. Macromolecules MOLECULES OF LIFE • 96% of the human body is composed of just four elements. They are carbon, hydrogen, oxygen, and nitrogen. These elements combine to larger units called molecules, which can combine into even larger units called macromolecules. • We eat macromolecules and digest them to molecules. We use these molecules to build whatever macromolecules we need for our cells and tissues. • There are two types of molecules in our bodies; organic and inorganic.

35. INORGANIC MOLECULES are not made of carbon atoms. • 1. SALTS are found in body fluids. They are needed for muscle contraction and nerve conduction. • 2. WATER The body is about 60% water. All of our body’s chemical reactions require it. • It keeps the body from overheating • It also prevents drastic changes in temperature. One spring, a baby finch collapsed with exhaustion on my patio. Since it was exhausted, it probably wasn’t good at finding food and water yet. That means it was dehydrated and hungry. I knew to get an eyedropper and give it water with sugar in it because those are the two main things it needs right away. We discussed water, now let’s get to sugars.

36. ORGANIC MOLECULES are made of carbon, which is what our body is mostly made of. The three main types of organic molecules in our body are carbohydrates, lipids, and proteins. 1. Carbohydrates (built from simple sugars) 2. Lipids (built from fatty acids) 3. Protein (built from amino acids) Nucleic acids (built from nucleotides)

38. CARBOHYDRATES are molecules that store energy a short time, compared to lipids. a) SIMPLE CARBOHYDRATES (known as sugars), such as those found in candy. They are used for a quick source of energy, and they are burned off fast. The main sugar form is glucose. b) COMPLEX CARBOHYDRATES (known as starch) is a storage form of glucose in plants. There is a lot of starch in flour and potatoes. When we eat breads and potatoes, we convert the starch to glucose. Starch does not break down into glucose easily (it takes energy), so they tend to get stored and are only broken down when there is not enough glucose available. c) CELLULOSE is only found in plant cell walls, and gives plant stems and leaves their firmness. Our body is unable to break down this substance, so it just passes through our digestive tract. That is what is referred to as eating fiber. It helps a person who has constipation. You may have heard the term cellulite referring to fat. Don’t confuse cellulite with cellulose.

39. Simple Carbohydrates (sugars) • Monosaccharides (single sugar) • Disaccharides (two sugars linked together) • Polysaccharides (more than two sugars linked together)

40. Monosaccharides (single sugar) • Contain carbon, hydrogen, and oxygen (water around the carbon) • Their major function - source of cellular energy (used in metabolism) • also used to build more complicated molecules

41. Disaccharides or double sugars (also used as energy or food for cells) Beer sugar Table sugar Milk sugar

42. Polysaccharides These are polymers (chains) of simple Sugars - uses: – energy storage in cells – attached to cell surfaces Plants store starch Animals store glycogen

43. 2. LIPIDS are made up of fatty acids. Theydiffer from carbohydrates in that they don’t dissolve in water. Two major categories: a) FATS AND OILS b) STEROIDS

44. a) FATS AND OILS: Fats are animal lipids, and oils are plant lipids. When we ingest (eat) oils, we convert them to fats. Function of fats • Fats are for long-term energy storage. • They also insulate against heat loss • Fat forms protective cushions around organs. 1) SATURATED FATTY ACIDS are solid at room temperature, like butter and lard. 2) UNSATURATED FATTY ACIDS are liquid at room temperature, such as vegetable oils

45. b) STEROIDS are lipids that have a very different structure than fats. Steroids are formed from cholesterol, which is found in the cell membranes of our body. Examples of steroids that our body makes are estrogen and testosterone.

46. Lipids: built from fatty acids • Contain C, H, and a little O • Greasy, oily, waxy molecules • Examples of fats and oils: - cholesterol – triglycerides – Phospholipids (cell membranes, communication) – Ear wax (protection) – Skin oils (lubrication) – Fat-soluble vitamins (vitamins A, D, E, K)

47. Adipose (Triglycerides) • Composed of three fatty acids bonded to a glycerol molecule • Used to STORE energy (fat) Fatty acids are hydrophobic- or water-hating!

48. Phospholipids • Two fatty acid groups (“tails”) and a phosphorus group (“head”) • Main use- major component of cell membranes Water-liking end Polar or hydrophilic Water-hating end Nonpolar or hydrophobic

49. Lipids made from one fatty acid • Cholesterol- all animal cells have this in the membrane • Steroids –modified cholesterol- estrogen, progesterone, testosterone (hormones)

50. 3. PROTEINS are molecules that make up most of our body. Our hair, nails, tissues, ligaments, cartilage, bone, tendons, muscles, and organs are made of proteins. Other proteins we have are enzymes, which function to break down larger molecules into smaller ones. In order to understand what a protein is, we have to talk about Amino Acids. a) AMINO ACIDS b) NUCLEIC ACIDS c) ATP