Welcome to Biology (SBI4U) University Preparation

1. Welcome to Biology (SBI4U) University Preparation Teacher: Ms. Karellas Email: georgia.karellas@yrdsb.ca Website: karellas.weebly.com

2. Course Outline Unit 1 - Biochemistry • Students will analyse the technological applications used in the food, pharmaceutical, and medical industries that affect biological processes and cellular functions. They will investigate how molecules and their chemical properties affect cellular processes and biochemical reactions. Students will demonstrate an understanding of the important structural and functional roles compounds play in the cells of all living organisms. Unit 2 - Metabolic Processes • Students will investigate the chemical changes and energy conversions that occur in metabolic processes. They will demonstrate the ways in which an understanding of metabolic processes enables people to make informed choices with respect to a range of personal, societal, and environmental issues. Unit 3 - Molecular Genetics • Students will demonstrate an understanding that DNA contains all the genetic information for any living organism. They will investigate how proteins control a wide variety of cellular processes. Students will assess the social, legal, and ethical implications of genetic research and biotechnology. Unit 4 - Homeostasis • Students will demonstrate an understanding of the strict limits on the internal conditions that organisms can tolerate. The will investigate the ways in which organ systems that maintain homeostasis rely on feedback mechanisms. Student will explore the environmental factors that affect homeostasis. Unit 5 - Population Dynamics • Students will demonstrate an understanding of how population growth follows predictable patterns. They will investigate how increased consumption of resources and production of waste is associated with population growth and results in specific stresses that affect Earth's sustainability. Students will assess technological developments that can contribute to or help offset the ecological footprint associated with population growth and the consumption of natural resources.

3. Unit 1: Biochemistry Introduction to Biochemistry: https://www.youtube.com/watch?v=tpBAmzQ_pUE

4. Prior understanding • Elements are pure substances that cannot be broken down through chemical or physical methods, elements consist of only one type of atom, an atom is the smallest component of an element that retains the properties of that element • A compound is a pure substance composed of two or more elements chemically combined, there is a specific ratio of types of atoms • Atoms contain a nucleus with protons and neutrons, protons are positively charged and neutrons have no charge • The number of protons defines the element i.e. Carbon has 6 protons • Negatively charged electrons travel in orbits (energy levels) around the nucleus, loss or gain of an electron causes the formation of a charged ion, electrons in the outer orbits are referred to as valence electrons, negatively charged ions are anions, positively charged ions are cations • The number of electrons in an uncharged atom is the same as the number of protons • The number of protons and neutrons determines the mass number of the element i.e. Carbon – 12 has 6 protons and 6 neutrons

5. Complete the Diagnostic

6. Lesson 1:Chemistry in Living Systems What is biochemistry? BRAINSTORM • Biochemistry: the branch of science dealing with the chemical and physiochemical processes that occur within living organisms.

7. Organic Chemistry What is the difference between organic and inorganic molecules? Organic molecules – usually contain CARBON and HYDROGEN Inorganic molecules – usually do not contain CARBON

8. Isotopes • elements that contain atoms with the same number of protons but different numbers of neutrons • the atomic number remains the same, the mass number changes • C-12 has a mass #12, 6 protons and 6 neutrons • C-13 has a mass # 13, 6 protons and 7 neutrons • C-14 has a mass # 14, 6 protons and 8 neutrons

9. C-12 makes up 99% of the carbon in nature, C-14 is a radioisotope that breaks down to release N-14, subatomic particles and energy • Radioisotopes decay in a predictable manner called the half-life (time taken for one half of the nuclei to decay)

11. Organisms take in radioactive carbon dioxide from the environment until the day they die but over time the radioactive carbon will decay but non-radioactive carbon will remain the same so the ratio of radioactive carbon to non-radioactive carbon can be used to date a specimen

12. Organic Elements and Bonding • electrons occupy volumes of space around the nucleus called orbitals or energy levels • 2 electrons occupy the first energy level (1s orbital), 8 electrons occupy the second energy level (2 in a 2s orbital, 6 in a 2p orbital) • the outermost s and p orbitals are valence orbitals, and the electrons in them are called valence electrons • the chemical behavior of elements is determined by these valence electrons

13. Organic Elements and Bonding • Atoms combine to make molecules. • The bonds between atoms of the same molecule (i.e. within the molecule) are intramolecular bonds. DEMO 

14. Organic Elements and Bonding The three types of intramolecular bonds are: • Non-Polar Covalent Bonds • Polar Covalent Bonds • Ionic Bonds

15. 1. Non-Polar Covalent Bonds Bond formed by sharing a pair of valence electrons between two atoms.

16. 2. Polar Covalent Bonds Bond formed by unequal sharing of a pair of valence electrons between two atoms. One atom is slightly negative; one is slightly positive (dipole)

17. 3. Ionic Bonds Bond formed by transfer of electrons from atom to atom. This results in the formation of positive cation, and negative anion. Ions are held together by electrostatic attraction.

18. Ions are important in living systems: • H+ ions are important in cellular respiration • Na+ ions are part of transport mechanisms that enable molecules to enter cells • Ca+ ions are involved in nerve transmission

19. The Role of Electronegativity • Electronegativity is a measure of an atoms ability to attract a shared electron pair in a covalent bond • Each element in the periodic table has an assigned electronegativity number (EN) - the larger the number, the greater the greater the pull on the electron pair • The element with the greater EN has a partial (δ-) charge, the element with the smaller EN has a partial (δ+) charge

20. ∆En is the difference between the electronegativity number between two atoms participating in a covalent bond • Electronegativity values can be found on a periodic table.

21. Electronegativity difference determines the BOND TYPE: • ∆En = 0 is when atoms share electrons equally, nonpolar covalent •  ∆En > 0 < 1.7 – one atom attracts the electrons more than the other, polar covalent bond  • ∆En > 1.7 or = 1.7 – electrons are gained by one atom, lost by the other, (anions and cations), ionic bond

22. ∆En ∆En ∆En 0 ---0.5--------------> 1.7 ---------------> 4.2 Non-polar polar covalent ionic

23. EXAMPLE: Bonds in Water (H2O) Oxygen electronegativity = 3.44 Hydrogen electronegativity = 2.2 Difference 3.44 – 2.2 = 1.24 Bond Type Polar covalent • In a water molecule the oxygen is slightly negatively charged because it has a higher electronegativity

24. Learning Check! Determine the type of bond: • KCl • CH4 • H2

25. Learning Check! Determine the type of bond: a) KCl K – 0.9 Cl – 2.9 2.9 – 0.9 = 2.0 ionic bond b) CH4 C – 2.5 H – 2.1 2.5 – 2.1 = 0.4 non-polar covalent c) H2 H – 2.1 2.1 – 2.1 = 0 nonpolar covalent

26. Organic Elements and Bonding • The bonds between molecule intermolecular bonds. • Weaker than intramolecular bonds DEMO  • Two types of intermolecular interactions are particularly important for biological system: hydrogen bonding and hydrophobic interactions

27. Hydrogen bonding: water is a polar molecule, attractions between (+) ends and (-) ends are called hydrogen bonds (see role of water) FON

28. Hydrophobic interactions: non-polar molecules such as cooking oil and motor oil do not form hydrogen bonds, but in the presence of polar molecules such as water, they tend to clump together, extruding water. • These are referred to as hydrophobic (water fearing) • Polar molecules that form hydrogen bonds with water are said to be hydrophilic(water loving) DEMO 

29. Why is WATER a special molecule? • Greater than 2/3 of body mass is water, lungs 90% water, bones 20% water, fat is 25% water • Controls body temperature, lubricates joints, shock absorber in brain and spinal cord and moisturizes surfaces • Polar covalent bonds and asymmetrical structure creates a highly polar molecule • Polarity of water allows it to form chemical bonds with other molecules (adhesion), itself (cohesion) and ions

30. ∆En ∆En ∆En 0 ---0.5--------------> 1.7 ---------------> 4.2 Non-polar polar covalent ionic

31. Learning Check! Determine the type of bond: a) KCl K – 0.9 Cl – 2.9 2.9 – 0.9 = 2.0 ionic bond b) CH4 C – 2.5 H – 2.1 2.5 – 2.1 = 0.4 non-polar covalent c) H2 H – 2.1 2.1 – 2.1 = 0 nonpolar covalent

32. POLAR vs. NON-POLAR BONDS RECALL: Intramolecular vs. Intermolecular bonds Electronegativity • Elements have varying electronegativity (EN): i.e. how strongly an atom can attract electrons • Non-Polar Covalent Bonds: the atoms involved have similar electro negativities, so the electrons are equally shared. (ex. H-H, O-O, C-H) • Polar Covalent Bonds: the atoms involved have different electro negativities, so there is unequal sharing of electrons. This results in a separation of charge. (ex. O-H)

33. ∆En ∆En ∆En 0 ---0.5--------------> 1.7 ---------------> 4.2 Non-polar polar covalent ionic

34. POLAR vs. NON-POLAR MOLECULES *Polar bonds ≠ Polar molecule *Non-polar bonds ≠ Non-polar molecule Polar Molecules • If the molecule is asymmetrical and has polar covalent bonds, the molecule will also be polar (e.g. glucose) • These molecules are “hydrophilic” (water loving) Non-Polar Molecules • Non polar molecules occur when a molecule has non-polar covalent bonds (e.g. C-H backbone) OR … • the polar covalent bonds are in a symmetrical arrangement (e.g. CCl4) • These molecules are “hydrophobic” (water hating)

35. Practice Questions: 1.Do the following groups contain polar or non-polar bonds? • -OH • -COOH • -NH2 • -PO4 • -CH2 2. Are the above groups hydrophobic or hydrophilic? 3. Are the following molecules polar or non-polar? 4. Why is this important for biology? (e.g. glucose, phospholipids)

36. Practice Questions: • Do the following groups contain polar or non-polar bonds? • -OH (polar) (hydrophilic) • -COOH (polar) (hydrophilic) • -NH2 (polar) (hydrophilic) • -PO4 (polar) (hydrophilic) • -CH2 (non-polar) (hydrophobic) • Are the above functional groups hydrophobic or hydrophilic? • Are the following molecules polar or non-polar? (polar) (non-polar) • Why is this important for biology? (e.g. glucose, phospholipids)

37. Functional Groups – (aka reactive clusters) • What are functional groups and why are they important? All the biological molecules we will be studying have important functional groups which determine their function and interactions in cells

38. With the exception of a few molecules (i.e. carbon dioxide) compounds containing carbon are referred to as organic compounds. The organic molecules of importance to living organisms can be classified into groups – carbohydrates, lipids, proteins and nucleic acids.

39. Carbon • 4 valence electrons can form 4 covalent bonds with other elements

40. attach to each other to form linear or branched or ring structures and therefore are the backbone of biological molecules • molecules with only carbon and hydrogen are hydrocarbons, non-polar due to the symmetrical arrangement of their bonds

41. other elements such as hydrogen, oxygen, sulfur, nitrogen and phosphorus may also attach to the carbon backbone to form functional groups

42. Functional Groups Create Study Cards for each functional group to REVIEW and ASSESS your learning of today’s lesson.

43. Macromolecules of Life

44. MINDS-ON: Macromolecule Sorting Activity! • Get into groups of 4 • Go to a station set up around the lab benches • Using your understanding of functional groups, sort the following molecules into the four categories of macromolecules (carbohydrates, lipids, proteins, and nucleic acids) – paste them on the sheet • First group to finish (correctly) gets a prize! 

45. Learning Goals: • Understand the structure and function of carbohydrates • Understand that monosaccharides are the smallest structural unit of carbohydrates • List and describe the 4 types of carbohydrates: monosaccharides, disaccharides, oligosaccharides, polysaccharides • Demonstrate condensation and hydrolysis reactions for carbohydrates

46. Macromolecules of Life What is a macromolecule? • Macromolecules: A large molecule (polymer) made of many smaller structural units (monomers) linked together 1)Carbohydrates 2)Lipids 3)Proteins 4)Nucleic Acids

47. Macromolecules are assembled and disassembled in the same way: Monomers  Polymer (Condensation/Dehydration Synthesis Reaction) • anabolic reaction - large molecules are built from small subunits • energy is required • Water is released

48. Macromolecules are assembled and disassembled in the same way: Polymer  Monomer (Hydrolysis Reaction) – hydro -water; lysis -broken • catabolic reaction - large molecules are broken down into small subunits • energy is released • Water is used

49. Carbohydrates (CHO)

50. Carbohydrates (CHO) What is the function of carbohydrates? • Used as sources of energy -Glucose: primary source of energy -Sucrose/Lactose: dietary sugars • Building materials • Cell surface markers for cell-to-cell communication