SA PT 1 Chemistry of Life

Basic Chemistry

A. Match the terms:

1. Atom — Smallest unit of matter that retains the properties of an element.

2. Element — A substance that cannot be broken down into simpler substances.

3. Neutron — A subatomic particle with no charge, found in the nucleus.

4. Electron — A negatively charged subatomic particle that orbits the nucleus.

5. Orbital — A region around the nucleus where electrons are likely to be found.

B. Match with Figure 2-1:

1. Electron — Small, negatively charged particle (label pointing to orbit).

2. Nucleus — Central part of the atom (dense center).

3. Neutron — Neutral particle within the nucleus.

4. Orbital — Region where electrons move (represented by shaded cloud).

5. Proton — Positively charged particle within the nucleus.

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Electrons and Chemical Bonds

1. Electrons — Involved in bonding, found in outer shell.

2. Ions — Charged atoms that have gained or lost electrons.

3. Ionic — Bond formed by the transfer of electrons.

4. Covalent — Bond formed by sharing electrons.

5. Double — Covalent bond with two shared pairs of electrons.

6. Triple — Covalent bond with three shared pairs of electrons.

7. Polar — Unequal sharing of electrons in a covalent bond.

8. Hydrogen — Weak bond between a hydrogen atom and another atom.

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Chemical Reactions

1. Reactants — Substances that start a reaction.

2. Products — Substances formed by a reaction.

3. Synthesis — Two or more substances combine to form a new compound.

4. Decomposition — A compound breaks down into simpler substances.

5. Exchange — Parts of molecules are exchanged.

6. Stored — Energy is stored in the bonds of molecules.

7. Released — Energy is released when bonds are broken.

8. Heat — Often released during chemical reactions.

9. ATP — Molecule that stores and transports energy in cells.

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Rate of Chemical Reactions

1. Increases — Rate increases with temperature or concentration.

2. Decreases — Rate decreases with lower temperature or concentration.

3. Catalyst — Substance that increases reaction rate without being consumed.

4. Enzymes — Biological catalysts that speed up chemical reactions.

5. Concentration — Amount of reactants affects reaction speed.

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Reversible Reactions

1. Reversible reaction — A reaction that can go forward or backward.

2. Equilibrium — State when forward and reverse reactions are balanced.

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Acids and Bases

A. Match the terms:

1. Acids — Substances that release hydrogen ions (H+).

2. Bases — Substances that release hydroxide ions (OH−).

3. Salts — Formed from the reaction of an acid and a base.

4. Buffers — Substances that minimize changes in pH.

B. pH descriptions:

1. Neutral solution — pH of 7 (equal H+ and OH−).

2. Acidic solution — pH below 7 (more H+).

3. Alkaline (basic) solution — pH above 7 (more OH−).

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Water

1. Heat — Water absorbs and retains heat.

2. Lubricant — Reduces friction between body parts.

3. Digestion — Involved in breaking down food.

4. Transport — Moves substances throughout the body.

5. Dissociate — Breaks ionic compounds into ions.

6. React — Participates in many chemical reactions.

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Organic Molecules

A. Match the terms:

1. Organic molecules — Contain carbon and hydrogen.

2. Inorganic molecules — Do not contain carbon-hydrogen bonds.

Carbohydrates:

1. Monosaccharides — Simple sugars like glucose.

2. Disaccharides — Two monosaccharides (e.g., sucrose).

3. Polysaccharides — Many monosaccharides (e.g., starch, glycogen).

Lipids:

1. Lipids — Fats and oils that are insoluble in water.

2. Fatty acids — Building blocks of lipids.

3. Triacylglycerol — Main form of stored fat.

4. Saturated — Fatty acids with no double bonds.

5. Unsaturated — Fatty acids with one or more double bonds.

Proteins:

1. Amino acid — Building block of proteins.

2. Essential — Must be obtained from diet.

3. Shape — Determines protein function.

4. Denaturation — Loss of protein shape and function.

5. Enzymes — Catalysts that speed up reactions.

6. Structural — Provide support and strength (e.g., collagen).

7. Contraction — Allow muscle movement (e.g., actin, myosin).

8. Activation energy — Energy required to start a reaction.

9. Lock and key — Model describing enzyme-substrate interaction.

Nucleic Acids:

1. Nucleotide — Building block of DNA and RNA.

2. DNA — Stores genetic information.

3. Chromatin — Loose form of DNA in the nucleus.

4. Chromosomes — Condensed DNA, visible during cell division.

5. RNA — Helps synthesize proteins.

6. DNA — Double-stranded, stays in nucleus.

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Quick Recall

1. Subatomic particles: Proton (+), Neutron (0), Electron (−)

2. Types of bonds: Ionic, Covalent, Hydrogen

3. Types of chemical reactions: Synthesis, Decomposition, Exchange

4. Influences on reaction rate: Concentration, Temperature, Catalysts, Enzyme activity

5. Four types of large organic molecules:

* Carbohydrates → Monosaccharides

* Lipids → Fatty acids + Glycerol

* Proteins → Amino acids

* Nucleic acids → Nucleotides

6. Three kinds of carbohydrates: Monosaccharides, Disaccharides, Polysaccharides

7. Three functions of lipids: Energy storage, Insulation, Cell membrane structure

8. Six functions of proteins: Enzymes, Structural support, Transport, Movement, Hormonal signaling, Immunity

9. Three functions of nucleic acids: Store genetic info, Transfer genetic info, Direct protein synthesis

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Word Parts

1. Neutral – neutron

2. Equal – isotonic

3. Together – synthesis

4. Many – polysaccharide

5. One – monosaccharide

6. Sugar – disaccharide

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### Mastery Learning Activity

1- Atoms are the basic building blocks of matter.

2- Atomic number equals number of protons.

3- A polar covalent bond has unequal electron sharing.

4- Monosaccharides combine to form polysaccharides.

5- Decomposition involves breaking down molecules.

6- All of the above describe functions of water.

7- Acids have more hydrogen ions than bases.

8- Buffers help maintain constant pH levels.

9- Water dissolves ions due to its polarity.

10- Glycogen is a polysaccharide used for energy storage.