Download presentation
1
Chapter 2 THE CHEMISTRY OF LIFE
2
California State Standards
1h: most macromolecules in cells and organisms are synthesized from a small collection of simple precursor 4e: proteins can differ from one another in the number and sequence of amino acids 1b: enzymes are proteins that catalyze biochemical reactions without altering the reactions equilibrium and the activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings
3
CHAPTER 2: THE CHEMISTRY OF LIFE
The first job of a biologist is to understand the chemistry of life. 2-1 The Nature of Matter A. Atoms · ___________= the basic unit of matter (has volume and mass; solid, liquid, gas, and plasma) · Atoms are made Atoms subatomic particles called protons, neutrons, and electrons
4
Carbon Atom - = neutrons _______________= Nucleus - center of an atom.
= electrons - Electronegative charge 1/1840 amu = protons - electrons travel in regions outside the nucleus called orbitals Positively charged 1 amu = neutrons - _______________= center of an atom. Home to protons and neutrons. Nucleus No charge 1 amu
5
· More than _____known kinds;
B B. Elements · Elements= · More than _____known kinds; · Found on the pure substances that consists entirely of one type of atom dozen are common in living organisms 100 Periodic table
6
Reading the Periodic Table Example: The element Carbon (only made of carbon atoms)
Atomic number = Number of protons in an atom; different for each element SYMBOL ____________ usually 1-2 letters ____________ of the element NAME _______________= # Protons + # neutrons in an atom; the average of one elements isotopes MASS NUMBER Isotopes are the various forms of an atom that differ based on the number of neutrons in the nucleus such as C 14. The isotopes that differ from the most common form are often radioactive or unstable.
7
C. Chemical Compounds 1. Chemical compound= Example: Sodium Chloride = Table salt Forms when sodium and chlorine combine in a 1:1 ratio 2. Chemical formula= Example: Sodium Chloride= NaCl 3. ____________________________ of a molecule Example: = white crystalline solid = a soft silvery metal that reacts explosively with water = poisonous greenish gas a substance formed by the combination of 2 or more elements in definite proportions. a short hand that shows chemical composition Chemical properties NaCl Na Cl
8
held together by links called chemical bonds.
Atoms in compounds are Involves the 2 main types of bonds are: ___________ and _________ held together by links called chemical bonds. interaction of electrons covalent ionic
9
1. Ionic Bonds a. b. ion= are formed by the transfer of one or more electrons from one atom to another. an atom that has a positive or negative charge as a result of gaining or losing electrons.
10
FORMING AN IONIC BOND +1 -1 Figure 2 3 Ionic Bonding
Sodium atom (Na) Chlorine atom (Cl) Sodium ion (Na + ) Chloride ion (Cl - Transfer of electron Protons +11 Electrons 11 Charge Protons +17 17 10 18 Section 2 1 Figure 2 3 Ionic Bonding +1 -1 c. Opposite charges attract creating a bond between the ions
11
2. Covalent Bonds a. formed by the b. Sharing means c. atoms sharing 2 electrons= __ electrons=double bond 6 electrons= d. _________________= The smallest unit of most chemical compounds (those joined with covalent bonds) sharing of electrons between 2 atoms. that the moving electrons are actually traveling in the orbitals of both atoms. single bond 4 triple bond Molecule
12
What property of water explains why this insect can stand on water?
2-2 What property of water explains why this insect can stand on water?
13
Why does ice float?
14
Ice is less dense than water.
Gas (water vapor) Solid (Ice) Liquid (water)
15
Water is Polar—uneven distribution of electrons
16
Hydrogen bonds
17
Water Cohesion & Adhesion
Water properties
18
Solution
19
Water has a pH of 7 which means that [H+] = [OH-]
Acids contain higher concentrations of [H+] ions than water. Bases contain lower concentrations of [H+] ions than water.
20
2-2 Properties of Water- Refer to reader’s guide
2-3 Carbon Compounds A. The Chemistry of Carbon 1. Carbon has ________________ which means carbon can form _________________ 2. Living organisms are made up of molecules that consist 3. Carbon can bond with itself forming 4 valence electrons 4 covalent bonds. of carbon, hydrogen, oxygen, phosphorus, nitrogen and sulfur. chains of unlimited length and form, rings, and complex structures.
21
4. The _____ groups of organic compounds found in living things are:
B. Macromolecules 1. Macromolecules= 2. Polymerization= 3. Monomers= 4. The _____ groups of organic compounds found in living things are: are giant molecules consisting of smaller molecules. process of joining small molecules to form large molecules small units that form polymers (large molecules) 4 carbohydrates lipids nucleic acids proteins Polymerization
22
PLANT CELL WALLS (CELLULOSE) POLYSACCHARIDE
Made of Example Function Monomer Carbohy-drate C,H,O 1:2:1 Glucose C6H12O6 1.Stores Energy -animals = -plants = 2. Structural Purposes - Monosaccharide = Mono + mono +mono= Lipids Mostly C, H Very little O Stores Energy 2. Form cell membranes Waterproof coverings 4. Chemical messengers 1 glycerol 3 fatty acids Saturated- Unsaturated- SINGLE SUGAR GLYCOGEN STARCH PLANT CELL WALLS (CELLULOSE) POLYSACCHARIDE CHITIN (INSECT EXOSKELETON) FATS OILS WAXES STEROIDS NO DOUBLE BONDS IN FATTY ACID AT LEAST ONE DOUBLE BOND
23
Challenge Question Why are most unsaturated fats liquid at room temperature?
24
Stores and transmits hereditary information
Made of Example Function Monomer Nucleic acids C H O P N Stores and transmits hereditary information Nucleotide= 1. 2. 3. Proteins methionine Shape determines function 2. pump small molecules in and out of the cell 3. aids in cell movement Amino acids DNA/RNA 5-C SUGAR PHOSPHATE GROUP NITROGENOUS BASE 20 KINDS HELPS CONTROL RATE OF REACTIONS (ENZYMES)
25
Carbohydrates
26
Lipids
27
Nucleic acids Nucleic acids are polymers of nucleotides joined together to make large macromolecules. The important nucleic acids are deoxyribonucleic acid(DNA) and various types of ribonucleic acids(RNA).
28
Proteins Protein are the building blocks of our body. We find protein in our bones, and muscles. We find protein in our hair and nails. There is protein in our brain, and also protein is part of our blood. Summary
29
Concept Map Concept Summary
Choose from the following: lipids, nucleotides, amino acids, fats and oils, sugars and starches, carbohydrates, nucleic acids, proteins Carbohydreat Carbon Compounds include Carbohydrates Lipids Nucleic acids Proteins that consist of that consist of that consist of that consist of Sugars and starches Fats and oils Nucleotides Amino Acids which contain which contain which contain which contain Carbon, hydrogen, oxygen Carbon,hydrogen, oxygen, nitrogen, phosphorus hydrogen,oxygen, nitrogen,
30
IQ Quiz: Chapter 2 What kind of compounds did we test in the lab?
What chemical was used to test for simple sugars? What was a positive result? If we want to see if peanuts have fat in them what could we do? How do we know if it is positive? What did copper sulfate and sodium hydroxide test for? If I had a bowl of cereal and Iodine fell into my cereal and turned a blue-black color what do I know is in my cereal? Name a food that had more than 1 compound in it? (tested positive for more than 1 test) What are the four most common elements in living things?
31
2-4 Chemical Reactions and Enzymes
A. Chemical Reactions =process that changes, or transforms one set of chemicals into another. Always involves changes in chemical bonds. 1. Reactants= 2. Products= elements or compounds that enter a reaction elements or compounds produced by a reaction EXAMPLE: HCl H + Cl
32
B. Energy in Reactions Activation Energy= C. Enzymes 1. Catalyst= energy that is needed to get a reaction started a substance that speeds up the rate of a chemical reaction without changing itself.
33
2. Catalysts ___________________________in a chemical reaction.
lower the activation energy Reaction with no enzyme AE without enzyme AE with enzyme reactants Reaction with an enzyme products
34
3. ______________ are ___________________ that speed up favorable (spontaneous) reactions.
4. Enzymes _____________ chemical reactions that take place in cells. 5. Enzymes are Enzymes biological catalysts speed up very specific D. Enzyme Action 1. The Enzyme-Substrate Complex a. Enzymes provide a site where reactants can be brought together to react (increasing the rate of reaction by reducing the activation energy)
35
Enzyme Activity Active site=
Figure 2 - 21 Enzyme Action Active site= Site on the enzyme where the substrate attaches Section 2 - 4 Enzyme Glucose (hexokinase) The reactants of a catalyzed reaction Substrates ADP Products Glucose - 6 - ATP phosphate Products are released Substrates bind to enzyme Substrates Enzyme-substrate complex are converted into products
36
-Ionic conditions (coenzymes)
b. Enzymes are not 2. Regulation of Enzyme Activity - Enzyme activity depends on environmental factors such as: · (enzymes in the stomach function best around pH=2) · (human enzymes function best around 37°C) consumed in the reaction; after products are formed, the enzyme is recycled. pH temperature -Ionic conditions (coenzymes) -Substrate concentration (greater the concentration the greater the rate of the reaction)
37
Warm-up questions Describe the difference between ionic and covalent bonds. Provide an example for each.
38
Warm-up 1. What are the 4 organic macromolecules which make up living organisms. 2. What are the monomers (building blocks) to these macromolecules.
39
Warm-up 1. What is a catalyst? 2. What are enzymes?
3. How do catalyst work? 4. What affects the activity of an enzyme?
40
Review The positively charged particle in an atom is the Neutron Ion
Proton electron
41
Review Two or more different atoms are combined in definite proportions in any Symbol Isotope Element Compound
42
Review A covalent bond is formed by the Transfer of electrons
Sharing of electrons Gaining of electrons Losing of electrons
43
Review When you shake sugar and sand together in a test tube, you cause them to form a Compound Mixture Solution suspension
44
Review A compound that produces hydrogen ions in solution is Salt Acid
Base polymer
45
Review In polymerization, complex molecules are formed by the joining together of Macromolecules Carbohydrates Polymers monomers
46
Review Proteins are polymers formed from Lipids Carbohydrates
Amino acids Nucleic acids
47
Review 9. An enzyme speeds up a reaction by Lowering activation energy
Raising activation energy Releasing energy Absorbing energy
48
Review In a chemical reaction, a reactant binds to an enzyme at a region known as the Catalyst Product Substrate Active site
49
Standardized Test Prep
An attraction between different substances Lower a chemical reaction’s activation energy The elements or compounds that enter into a chemical reaction Choose: Cohesion Adhesion Catalysts Reactants Products
50
STP Which one of the following is NOT an organic molecule found in living organisms Protein Nucleic acid Carbohydrate Sodium chloride lipid
51
STP Which combination of particle and charge is correct? Proton: +
Electron: + Neutron: - Proton: - Electron: 0
52
STP In which of the following ways do isotopes of the same element differ? # neutrons only #protons only #neutrons and protons #protons and mass #neutrons and mass
53
STP Which of the following molecules is made up of glycerol and fatty acids? Sugars Starches Lipids Nucleic acids Proteins
54
STP Nucleotides consist of a phosphate group, a nitrogenous base, and a Fatty acid Starch Lipid 5 carbon sugar 6 carbon sugar
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.