Bellwork What is the basic structure of an atom?

1. BellworkWhat is the basic structure of an atom?

2. Honors Biology- Chapter 2: Biochemistry Ch. 2.1- Basic Chem

3. Target #1- I can explain matter and describe what it is composed of • Matter: refers to anything that takes up space and has mass • Exists in 4 states on Earth: solid, liquid, gas, and plasma • Composed of basic substances called elements • Element: a substance that cannot be broken down to simpler substances with different properties by ordinary chemical means • 92 naturally occurring elements • Elements basic to life: carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur

4. Target #2- I can state what an atom is • Elements consist of tiny particles called atoms • Atoms: the smallest part of an element that displays the properties of an element • Consists of subatomic particles • Protons • Neutrons • Electrons • Most of the atom is empty space

5. Target #3- I can identify the atomic number and atomic mass of an element • All atoms of an element have the same number of protons • Known as the atomic number • Makes each atom unique • Written as a subscript in the lower left of the atomic symbol • Atomic Mass: • The sum of it’s protons and neutrons

6. Periodic Table • Constructed as a way to group the elements according to their characteristics • Arranged in increasing order of atomic number • The vertical columns are groups • Horizontal rows are periods Target #4- I can describe the periodic table of the elements

8. To determine the number of protons… • …look at the atomic number • To determine the number of electrons… • …look at the atomic number (hint: unless the atoms does not have a neutral charge, the # of protons= the # electrons • To determine the number of neutrons… • ….subtract the number of protons from the atomic mass Target #5- I can determine the number of protons, neutrons, and electrons in an element

9. Protons = • Electrons= • Neutrons= • Protons= • Electrons= • Neutrons=

10. Target #6- I can explain how elements change when they become isotopes • Isotopes: atoms of the same element that differ in the number of neutrons • Have the same number of protons, but different atomic masses • Changing the number of neutrons does not change the identify of the element, just the atomic mass of the element • Ex: Carbon 14 • In low doses Used as “tracers” or a tag to detect molecular changes • Ex: detection of thyroid conditions • In high doses can cause damage to cells, DNA, and cancer

11. The Bohr’s model provides a basic layout for where electrons are located in an atom • Electrons “circle” the nucleus in the electron cloud • Layers in the electron cloud are called orbitals • Each orbital has a designated number of electrons which fill it • 1st orbital= 2 electrons • 2nd orbital= 8 electrons Target #7- I can explain how electrons are position in an atom using the Bohr model

12. Target #8- I can state the octet rule • The Octet Rule: states that the outer orbital is most stable when all 8 electrons are present • Applies when concerning bonding of different atoms • Atoms can give up, accept, or share electrons in order to meet the octet rule

13. Honors Biology- Ch. 2 Biochemistry Ch. 2.2: Molecules & Compounds

14. Target #9- I can differentiate between a molecule and a compound • Molecule: formed when 2 or more atoms bond together • Ex: oxygen gas is known as O2 • Compound: when atoms of two or more different elements bond together • Ex: water H2O

15. Target #10- I can describe how an ion forms • Ions form when electrons are transferred from one atom to another • Ex: Na (Sodium), with 1 electron in it’s 3rd orbital, tends to donate it’s electron. Cl (chlorine) has the tendency to accept electrons • NaCl • Causes a charge imbalance in each atom • Na has one more proton than electron, therefore it has a net charge of +1

16. Target #11- I can describe an ionic bond • Ionic compounds are held together by ionic bonds • Occurs between negatively and positively charged ions • Most commonly found in disconnected form in biological systems because the elements dissolve in water

17. Target #12- I can describe a covalent bond • Covalent bond • Results when two atoms share electrons • Both atoms follow the octet rule because their outer orbital is complete

19. Target #13- I can identify how many electrons are bonded covalently through atomic symbols • Atoms sharing electrons are symbolized by drawing a line between the two atoms • If atoms share 2 electrons, they form a double bond • If atoms share 3 electrons, they form a triple bond

20. When the sharing of electrons between two atoms is fairly equal, the covalent bond is a non-polar covalent bond • Ex: Methane • When the sharing of electrons between two atoms is unequal, the covalent bond is a polar bond • Ex: Water Target #14- I can differentiate between polar and non-polar covalent bonds

21. Target #15- I can describe a hydrogen bond • Polarity within a water molecule causes the hydrogen atoms in one molecule to be attracted to the oxygen atoms in another molecule • Bond called a hydrogen bond • Weaker than ionic or covalent bond, so it can be broken easily • Found in substances like water, and holds the strands of DNA together

22. Bellwork Why is water important?

23. Ch 2- Biochemistry Ch. 2.3 Chemistry of Water

24. Quick review • Hydrogen and Oxygen covalently bond together to form water • Water molecules have polar covalent bonds • The oxygen and hydrogen share the electrons unequally creating a positive side and a negative side • Hydrogen positiveOxygen negative • Water molecules are attracted to each other, which creates hydrogen bonds • The positive Hydrogen and negative Oxygen are attracted to each other

25. Target #16- I can describe the different properties of water • Water has high heat capacity • Calorie: the amount of heat energy needed to raise the temperature of 1 gram of water 1oC • Requires more energy to heat water than most other liquids • The hydrogen bond that link water molecules together helps water absorb heat without a great change in temperature • Because the temperature of water rises and falls slowly, organisms are better able to maintain their normal internal temperatures and are protected from drastic weather changes

26. Target #16- cont. • Water has a high heat of vaporization • Water requires a lot of heat energy to turn water from a liquid to a gas • The hydrogen bonds must be broken before water turns into steam • Gives animals in a hot environment an efficient way to release excess body heat • When an animal sweats, the heat from the animal vaporizes the water to cool the animal down • The ocean absorbs and stores solar heat, which explains the consistent temperatures found at the shore

27. Target #16- cont • Water is a solvent • Due to its polarity, water facilitates chemical reactions • Helps to dissolve a number of substances • Ex: salt the charged ends of the water molecules are attracted to the positive Na+ ion and the negative Cl- ion, which are then pulled apart by the water molecule • Hydrophilic: molecules that can attract water • Hydrophobic: molecules that cannot attract water

28. Target #16- cont. • Water molecules are cohesive and adhesive • Cohesion allows water molecules flow freely, but also do not separate from each other due to hydrogen bonding • Adhesion occurs due to water’s positive and negative ends which allow it to adhere to polar surfaces • Allows water to be an excellent transport system • Water has a high surface tension • Caused by hydrogen bonding • Ex: insects like the water strider can walk on the surface of water due to surface tension

29. Target #16- cont • Frozen water is less dense than liquid water • As water cools, the molecules come closer together • Creates a crystal lattice that is rigid and more open • Explains why water expands when it freezes • Also explains why ice cubes float at the top of a glass

30. When water ionizes (separates), it releases hydrogen ions & hydroxide ions • H2O H+ + OH- • Acidic solutions • Substances that release hydrogen ions when they dissolve in water • Acidic solutions have a high concentration of H+ ions than OH- ions • Basic solutions (Alkaline) • Substances that either take in H+ ions or release OH- ions • Alkaline solutions have a higher concentration of OH- ions than H+ ions Target #17- I can differentiate between acidic and alkaline solutions

31. Target #18- I can explain the pH scale and the importance of buffers • pH scale • Used to indicate the acidity or alkalinity of solutions • Ranges from 0 – 14 • 0-6 = acid • 7 = neutral • 8 – 14 = basic • Buffers • A buffer is a chemical or a combination of chemicals that keeps pH within normal limits • Ex: bufferin, shampoo, and deodorant • Helps to balance systems • Ex: acid in our stomachs is too strong for our intestines

32. Bellwork What is the scale for pH and how does it relate to acidity and alkalinity?

33. Ch. 2- Biochemistry Ch. 2.4- Intro to Organic Molecules

34. Target #19- I can differentiate between inorganic and organic molecules • Inorganic molecules constitutes non- living matter that play important roles in living things • Ex: NaCl • Organic molecules constitutes living matter • Always contains carbon and hydrogen • Accounts for the formation of a variety of organic molecules • A carbon atom has 4 electrons in the outer orbital • Can share electrons with as many as 4 other atoms • Can create long hydrocarbon chains • Macromolecules • Known as the “molecules of life” • Made most of elements like carbon and hydrogen

35. Monomer: a simple organic molecule that exists individually • A basic unit of a macromolecule • Polymer: many monomers linked together • Linked through a dehydration reaction • Removal of a water molecule • Each macromolecule has a corresponding monomer and polymer • Types of macromolecules • Proteins • lipids • Carbohydrates • Nucleic acids Target #20- I can differentiate between a monomer and a polymerTarget #21- I can list the 4 macromolecules

36. Bellwork In what food or organisms do we find carbohydrates?

37. Ch. 2- Biochemistry Ch. 2.5- Carbohydrates

38. Target #22- I can describe a carbohydrate • Carbohydrates • Function for quick fuel and short-term energy storage • Play a structural role in woody plants, bacteria, and animals like insects • Are involved in cell-to-cell recognition • Characterized by the presence of the atomic grouping H-C-OH

39. The monomer of carbohydrates is a monosaccharide • Ex: glucose • Glucose is used as an immediate source of energy in both plants and animals • Ex: fructose • Found in fruits • Disaccharide: contains two monosaccharides that have joined together • Ex: sucrose & lactose • The polymer of a carbohydrate is a polysaccharide Target #23- I can identify the monomer and polymer of carbohydrates

40. Target #24- I can identify the 3 polysaccharide molecules of carbohydrates • Starch is a storage molecule in plants • Glycogen is a storage molecule in animals • Found in the liver • Cellulose is found in plant cell walls • Makes plants hard to digest

41. Bellwork In what foods or organisms do we find proteins?

42. Ch 2- Biochemistry Ch. 2.7- Proteins

43. Target #25- I can describe a protein • Perform many functions • Provides support structures • Keratin hair and nails • Collagen ligaments, tendons, and skin • Controls metabolism • Some proteins are enzymes • Enzymes speed chemical reactions • Hormone production • Muscle function • Transportation of molecules in the blood • Cellular transport of molecules

44. The monomer of a protein is an amino acid • There are 20 different amino acids • Identified by 3 components • Amino group • Acidic group • R group • Varies in structure • Has several different elements, including carbon and hydrogen Target #26- I can describe an amino acid

45. The polymer of a protein is a polypeptide • Made up of 2 or more amino acids • Amino acids are bonded via a polypeptide bond • Occurs between the oxygen, carbon, nitrogen, and hydrogen atoms • Each polypeptide differs by the sequence of its R groups Target #27- I can describe a polypeptide and how it bonds

47. Target #28- I can explain the levels of protein organization • Primary structure • Determined by the sequence of amino acids that form the polypeptide • Looks like a chain

48. Target #28- cont. • Secondary structure • The polypeptide chain coils into a spiral called an alpha helix, or a folded structure like pleats called a beta pleated sheet • Held together by hydrogen bonds

49. Target #28- cont. • Tertiary structure • The final 3 dimensional shape that makes up the polymer of a protein, the polypeptide • Alpha helix structures bond to beta pleated sheets • Bonding occurs covalently between R groups

50. Target #28- cont • If a protein has more than 1 polypeptide, each polypeptide bonds together to form a quaternary structure protein