Keystone review 1

1. Keystone review 1 Biochemistry through DNA/protein synthesis

2. Biochemistry • What is an atom? • An atom is the most basic unit of structure. Each element on the period table, such as carbon, hydrogen and oxygen, are made up of atoms. • Atoms consist of three particles • Protons: have a positive charge • Electrons: have a negative charge • Neutrons: have a neutral charge • What are compounds? • Compounds form when atoms join together, like water, which is hydrogen atoms and oxygen atoms bonded together.

3. Biochemistry • What is a bond? • The sharing or transferring of electrons in the atom’s outer “shell” • Sharing electrons: covalent bond • Transferring electrons: ionic bond • Hydrogen bonds from between hydrogen atoms and other atoms

4. Biochemistry • What’s so special about carbon? • Carbon has 4 electrons in it’s outer shell so it can form 4 bonds • Carbon is found in all of the macromolecules such as • Proteins • Lipids (fats) • Carbohydrates • Nucleic acids (DNA material)

5. Biochemistry • What’s so special about water? • Water (hydrogen atoms + oxygen atoms) is a polar molecule • Polarity refers to the distribution of electrons between two atoms (that are sharing their electrons) • Water is considered polar because the hydrogen atom’s electrons are shared UNEQUALLY with the oxygen atom’s electrons • Polar Nonpolar

6. Biochemistry • What’s so special about water? • It’s attracted to some substances and it repels others • Hydrophobic: water-hating. These substances don’t mix with water • Ex: Oil • Hydrophilic: water-loving. These substances DO mix and dissolve in water • Ex: Sugar

7. Biochemistry • What’s so special about water? • Water is a natural buffer, meaning it stabilizes the pH of substances • Acid: any substance that releases hydrogen ions (H+) when dissolved in water • Ex: lemon juice, hydrochloric acid • Base: any substance that releases hydroxide ions (OH-) when dissolved in water • Ex: ammonia, bleach

8. Biochemistry • What’s so special about water? • Water molecules have sticky properties • Adhesion: when water sticks to other surfaces • Think: water sticking to your car windshield • Cohesion: when water molecules stick to one another • Think; water forming droplets • Surfacetension: when water forms a surface that resists external forces • Think: belly flopping off the diving board • Capillaryaction: when water flows against gravity up a plant stem • Think: paper towel soaking up water

9. Biochemistry • Macromolecules • Proteins • Lipids • Carbohydrates • Nucleic acids • Made up of monomers (building blocks) • Macromolecules build together to make cell structures, which build together to make us!

10. Biochemistry • Proteins • Monomer: amino acid • Elements that make up proteins: carbon (C), nitrogen (N), oxygen (O), hydrogen (H) and sometimes sulfur (S) • Function/propose: make up muscles, act as markers on cells (identify the cell as a special type), act as enzymes that speed up reactions, fight disease and transport materials into and out of cells • Reaction: amino acids are joined together through a reaction called dehydration synthesis. Two amino acids are joined together by a bond called a peptide bond

11. Biochemistry • Amino acids are made up of a central carbon that is attached to a carboxyl group (COOH), a hydrogen, an amino group (NH2) and a “R” group • R groups differ from one amino acid to another, making each amino acid unique • There are 20 amino acids in existence Alanine Serine

12. Biochemistry • When amino acids join together (through a reaction called dehydration synthesis, and by a bond called a peptide bond), they from a polypeptide • A polypeptide is a chain of amino acids • Polypeptides=proteins

13. Biochemistry • Enzymes are types of proteins. Their job is to speed up reactions and act as catalysts. • Enzymes fit, like a lock and key, with a substrate. The place where they join is called the activation site. • A substrate is what the enzymes acts on. • EX: lactose intolerance • Lactose is a sugar found in dairy products. Normally, there is an enzyme that occurs naturally in a person’s body. When they consume dairy products, and their body is filled with the lactose sugar, the enzyme lactase acts on the lactose sugar and breaks it down so it can be digested. People with lactose intolerance are lacking the enzyme (or it doesn’t function properly) lactase, so when they eat dairy products and take in the lactose sugar, they are unable to digest it and they have stomach “issues” as a result.

14. Biochemistry • This is not the only function of enzymes. • Enzymes also speed up reactions so that your body doesn’t have to use all of it’s energy (that it gets from breaking down food) on simple tasks like breathing. • Enzymes are never used up, but can be affected by things like pH, temperature and salt concentration. These things can alter an enzyme’s shape, making it impossible for the substrate and the enzyme to fit properly.

16. Biochemistry • Lipids are fats, oils, steroids, and waxes • Monomer: Fatty acid • Elements: Carbon (C), hydrogen (H), Oxygen (O). They have HIGH amount of hydrogen atoms (for every 1 carbon there are 2 hydrogens) • Function/purpose: Fats provide cells with protection and insulation, steroids are our hormones, waxes provide waterproof coverings (ear wax or waxy plant leaves like ivy). Lipids make up the cell membrane (lipid bilayer!)

17. Biochemistry • Different types of lipids • Saturated: fats that have single (covalent) bonds between the carbon atoms • Unsaturated: fats that have some double (covalent) bonds between the carbon atoms. The electrons are shared twice, in a sense. • Polyunsaturated: fat that have many double (covalent) bonds between the carbon atoms.

19. Biochemistry • Carbohydrates • Monomer: monosaccharide • Elements: Carbon (C), Hydrogen (H) and Oxygen (O) • Function/propose: main source of energy for the body • Reaction: Dehydration synthesis joins two monosaccharides together.

20. Biochemistry • Disaccharides: two monosaccharides joined together • Polysaccharides: many monosaccharides joined together

21. Biochemistry • Nucleic acids • Monomer: nucleotide • Elements: Carbon (C), Oxygen (O), Nitrogen (N), Phosphorus (P), and Hydrogen (H) • Base: Adenine, thymine, cytosine, and guanine • Sugar: a monosaccharide • Phosphate bonded to 3 hydrogens • Function/purpose: DNA (the heredity molecule that stores genetic information, RNA (like DNA’s simpler form), ATP and NAD (energy storing molecules involved in photosynthesis and cellular respiration reactions)

22. Biochemistry • Two types of bases: pyrimidine and purines. • Adenine (A) and guanine (G) are purines • Thymine (T) and cytosine (C) are pyrimidine

23. Cells • The cell membrane • Function: to control what enters and exits the cell • Composition: a phospholipid bilayer (two layers of fats) • Arranged tail to tail

24. Cells • Also embedded in the cell membrane are • Proteins: help large molecules move into and out of the cell • Peripheral protein: on the surface of the cell (mostly involved in cell identification and recognition) • Integral protein: go the entire way through the membrane (helps molecules get into and out of the membrane, like a tunnel!) • Cholesterol: makes the membrane more rigid

25. Cells • Transport into and out of the cell • Passivetransport: doesn’t require energy • Molecules move by diffusion: the movement of molecules from a high concentration to a low concentration • THINK: does it take energy to ride a bike from high on a mountain to low on a mountain? • Solute: the solid substance being dissolved (sugar, salt etc.) • Solvent: the liquid substance doing the dissolving (usually water)

26. Cells • Diffusion occurs when a “system” is not a equilibrium • Equilibrium is when all things are equal • Solutes move from high  low until there is an equal amount on each side (of the cell, inside/out) • Things that affect diffusion • Temperature: a system at a higher temperature will cause diffusion to occur more quickly. THINK: does hot chocolate powder dissolve faster in hot water or cold water? • Size: larger solute molecules diffuse slower into/out of a system or a cell. THINK: human running through a jell-o wall vs. an ant

27. Cells • Osmosis is the diffusion of specifically WATER into or out of a cell • Cells need water to live but too much water can be fatal • Types of tonicity • Hypertonic solutions: cause the cell to shrink because water is leaving the cell. • Why is water leaving? The concentration of water inside the cell is greater than the concentration of water outside of the cell, so the water moves from high to low OUT OF THE CELL • Hypotonic solutions: cause the cell to swell because water is entering the cell. • Why is water entering? The concentration of water inside the cell is lesser than the concentration of water outside the cell, so the water moves from high to low INTO THE CELL

28. Cells • Isotonic solution: water moves into and out of the cell at an equal rate Cytosol is the gel-like fluid inside a cell (in this case, a red blood cell)

29. Cells • Facilitated diffusion: molecules that need help crossing the membrane use proteins as tunnels. They still move from a high concentration to a low concentration. Glucose High concentration Low concentration Phospholipid bilayer Integral protein

30. Low Concentration Cell Membrane High Concentration Protein channel Glucose molecules

31. Cells • Active transport: requires energy to move molecules from a low concentration to a high concentration • THINK: does it require energy to move a bike from low on a mountain to high on a mountain? • Pumps are required to move the molecules

32. Cells • Endocytosis - cell membrane engulfs and takes in materials • Phagocytosis - solid material taken in • Pinocytosis - liquid material take in

33. Cells • Vesicles, sacs that are carrying either solid or liquid materials, fuse with the cell membrane and release their contents or take in contents

34. Cells • Types of cells • Prokaryotic cells: cells that lack a nucleus and other internal organelles. • Ex: bacteria • Eukaryotic cells: cells that contain a nucleus and other internal organelles • Ex: plant cells and animal cells • Organelles: “tiny organs” inside the cell that help the cell carry out various processes and functions to keep it alive

35. Organelles • Cell membrane • Found in both plant and animal cells (and prokaryotic cells like bacteria) • Surrounds the cell and provides protection • Controls what enters and exits the cell

36. Organelles • Cell wall • Found surrounding plant cells (eukaryotic) and bacteria cells (prokaryotic) • Provides extra support and structure for the cell

37. Organelles • Nucleus • Found in both plant and animal cells • Brain of the cell. Controls all cell functions. Where DNA is located • Has a membrane around it, called the nuclear membrane • Material (such as RNA) can enter and leave the nucleus • Has an inner core known as the nucleolus where ribosomes are made

38. Organelles • Mitochondria • Found in both plant and animal cells • Known as the powerhouse of the cell because it makes energy for the cell. Involved in cellular respiration. • Has two membranes surrounding it • Has folds inside, which are called cristae

39. Organelles • Vesicles • Found in both plant and animal cells • Small sacs or pouches that transport materials around the cell • Involved in exocytosis and endocytosis • Types • Peroxisomes: found in both plant and animal cells. They break down fatty acid chains • Lysosomes: found in only animal cells. Contain digestive enzymes that help clean up the cell

40. Organelles • Ribosomes • Found in both plant and animal cells • Made by the nucleolus • Attach themselves to the rough endoplasmic reticulum • Responsible for attaching to RNA and aiding in translation, which is the process of making proteins

41. Organelles • Rough endoplasmic reticulum • Called rough ER for short • Found in both plant and animal cells • Responsible for transporting proteins. • Smooth endoplasmic reticulum • Called the smooth ER for short • Found in both plant and animal cells • Responsible for breaking down fats and toxic substances

42. Organelles

43. Organelles • Golgi body (apparatus) • Found in both plant and animal cells • Responsible for modifying proteins that are made by the rough ER and ribosomes and then packaging them for distribution by vesicles

44. Organelles • Chloroplasts • Found only in plant cells • Responsible for preforming photosynthesis • Green in color because they contain the pigment chlorophyll

45. Organelles • Vacuole • Found in both plant and animal cells • Responsible for storing water and other important materials • Can expand or shrink depending on the needs of the cell

46. PHOTOSYNTHESIs Reactants Sunlight + 6CO2 + 6H2O C6H12O6 + 6O2 Products

47. Photosynthesis • The process of taking light energy and converting it into chemical energy ( sugars) • 3 stages of photosynthesis • Energy capture from sunlight • Light energy is converted into chemical energy and stored in a molecule of ATP or NADPH • Chemical energy stored in ATP or NADPH is used to make organic compounds ( sugars)

48. ATP • A nucleotide with two extra energy-storing phosphate groups H20 + ATP  ADP + P + energy Water + ATP  adenosine diphosphate + phosphate + energy • Cell use the energy released by this reaction to power metabolism.

50. Plant parts • Stomata: openings in plant leaves and stems where gas exchange occurs • Mesophyll: plant tissues • Chloroplasts: organelle that does photosynthesis