Chemistry: Atomic Structure and Bonding

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Questions and Answers

What is one key function of carbohydrates?

Store genetic information

Insulate organs

Provide short-term energy (correct)

Act as hormones

Saturated fatty acids contain double bonds between carbon atoms.

False

What are the three main types of lipids?

Triglycerides, phospholipids, steroids

A buffer is a substance that helps maintain the ______ of a solution.

pH Signup and view all the answers

Match the following terms with their correct definitions:

Covalent = Sharing of electron pairs between atoms Ionic = Transfer of electrons from one atom to another Amphipathic = Molecule containing both a hydrophilic and hydrophobic part Hydrolysis = Chemical process that splits molecules by adding water Signup and view all the answers

Which of the following correctly describes ionic and covalent bonds?

Ionic bonds involve the transfer of electrons, while covalent bonds involve the sharing of electrons. Signup and view all the answers

Is the term 'isotope' and 'allotrope' interchangeable in chemistry?

False Signup and view all the answers

What unique property of carbon allows its atoms to form a large number of different molecules?

Carbon's ability to form four covalent bonds. Signup and view all the answers

Substances that do not dissolve in water are considered , while those that do dissolve are referred to as .

hydrophobic; hydrophilic Signup and view all the answers

Match each biomolecule class with its primary feature:

Carbohydrates = Energy storage and structural components Proteins = Catalysts and structural support Lipids = Long-term energy storage and membrane formation Nucleic Acids = Genetic information storage and transmission Signup and view all the answers

What is the relationship between polymers and monomers?

Polymers are made up of repeating units called monomers. Signup and view all the answers

Describe the process that produces ADP from ATP.

The process of hydrolysis releases a phosphate group from ATP, converting it to ADP while releasing energy. Signup and view all the answers

The property of water that allows it to rise through narrow tubes is known as ______.

capillary action Signup and view all the answers

Study Notes

Atomic Structure and Bonding

Atom: The fundamental unit of matter.
Element: A substance made of only one type of atom.
Molecule: A group of two or more atoms bonded together.
Compound: A substance formed by the chemical combination of two or more different elements.

Subatomic Particles

Diagram: A simple sketch of an atom with a nucleus containing protons (positive charge, mass ≈ 1 amu) and neutrons (neutral charge, mass ≈ 1 amu). Electrons (negative charge, virtually no mass) orbit the nucleus in electron shells/clouds.

Isotopes vs. Allotropes

Isotope: Atoms of the same element with different numbers of neutrons, but the same number of protons. They have identical chemical properties
Allotrope: Different forms of the same element, with different molecular structures. They have different physical properties.

Bonds

Ionic Bond: Transfer of electrons from one atom to another, forming ions with opposite charges that attract.
- Example: Sodium Chloride (NaCl).
Covalent Bond: Sharing of electrons between atoms. - Example: Water (H₂O)
Intramolecular Force: Forces within a molecule. Ionic and covalent bonds are considered intramolecular forces.
Intermolecular Force: Forces between molecules. (e.g., hydrogen bonds)

Carbon's Uniqueness

Carbon's ability to form four covalent bonds allows it to form a vast number of complex molecules with diverse structures.

Water Molecule

Sketch: Represent water molecules as bent shapes with the oxygen atom in the center, bonded to two hydrogen atoms. Show hydrogen bonds between slightly positive hydrogen atoms and slightly negative oxygen atoms of adjacent water molecules. Label partial charges accordingly.

Polar vs. Nonpolar Molecules

Polar Molecules: Molecules with an uneven distribution of charge, resulting in a positive and negative end (dipole). This is due to differences in electronegativity between atoms within the molecule.
Nonpolar Molecules: Molecules with an even distribution of charge, no distinct positive or negative end. These typically result from symmetrical bonding of atoms with similar electronegativity.

Dissolving in Water

Hydrophilic: Substances that dissolve in water. This typically involves polar molecules interacting with water's polar properties.
Hydrophobic: Substances that do not dissolve in water. This tends to involve nonpolar molecules repelling water molecules.

Properties of Water

Cohesion: Water molecules stick to each other through hydrogen bonding. (Drawing: Show water molecules close together, connected through hydrogen bonds).
Adhesion: Water molecules stick to other polar surfaces. (Drawing: Water molecule seemingly clinging to a surface. This would be polar).
Capillary Action: The ability of water to move against gravity in narrow tubes. (Drawing a tube with water drawn upward. Capillary action would mean narrower tubes would have a greater draw).
Surface Tension: The resistance to an increase in its surface area. (Drawing: Water molecules drawn close together at the surface resisting the increase in its surface area).
Specific Heat Capacity: The amount of heat required to raise the temperature of a substance by a certain amount. (Drawing: Water drawing out an external heat source. Water needs more energy to raise the temp.).

Biomolecules

Carbohydrates: Primary energy source. (Monosaccharides --> Polysaccharides).
Lipids: Energy storage, insulation, and cell membranes. (Fatty acids + Glycerol --> Triglycerides, Phospholipids, Steroids).
Proteins: Structural support, enzymes, transport, and defense. (Amino acids --> Polypeptides).
Nucleic Acids: Storage and transmission of genetic information. (Nucleotides --> DNA and RNA).

Identifying Biomolecule Types

Diagram Analysis: Look for the presence of specific functional groups, repeating units (monomers), and overall shape.

Monomers and Polymers

Monomer: A single repeating unit in a polymer.
Polymer: A large molecule (macromolecule) composed of repeating monomers.
- Carbohydrates: Monomers: monosaccharides (glucose, fructose); Polymers: polysaccharides (glycogen, starch, cellulose).
- Lipids: Monomers: fatty acids and glycerol (in triglycerides); no true repeating monomers.
- Proteins: Monomer: amino acids; Polymer: polypeptide/protein.
- Nucleic Acids: Monomer: nucleotides; Polymer: DNA and RNA.

Polymerization and Depolymerization

Dehydration Synthesis: Removes water to form a bond between monomers.
Hydrolysis: Adds water to break a bond between monomers.

ATP and ADP

ATP (adenosine triphosphate) loses a phosphate group to become ADP (adenosine diphosphate), a process that releases energy.

Carbohydrate Functions

Carbohydrates provide short-term energy, but also have structural functions (e.g., cellulose in plant cell walls).

Carbohydrates and Lipids

Similarities: Both are important sources of energy.
Differences: Carbohydrates are generally hydrophilic; lipids are hydrophobic, making them good for long-term energy storage.

Fatty Acids

Unsaturated: One or more double bonds between carbon atoms; usually liquid at room temperature.
Saturated: No double bonds between carbon atoms; usually solid at room temperature.
- Structure-Property Relationship: The presence of double bonds in unsaturated fats creates kinks in the molecule's structure, preventing them from packing tightly together and lowering the melting point.

Lipids - Types

Triglycerides: Energy storage.
Phospholipids: Cell membranes.
Steroids: Hormones and cholesterol

Protein Structure and Function

Amino Acid Structure: The specific sequence and arrangement of amino acids determine a protein's unique shape and function.
Organization Levels: Primary (sequence), secondary (alpha-helix or beta-sheet), tertiary (3D folding), and quaternary (multiple polypeptide chains).

Nucleotide Structure

Sketch: Include a pentose sugar (deoxyribose in DNA, ribose in RNA), a phosphate group, and a nitrogenous base (adenine, thymine, cytosine, guanine or adenine, uracil, cytosine, guanine)

DNA vs. RNA

Similarities: Both are nucleic acids, composed of nucleotides, and carry genetic information.
Differences: DNA is double-stranded; RNA is single-stranded, DNA uses thymine; RNA uses uracil, DNA is stable; RNA is more versatile.

DNA Ladder

Rungs: The nitrogenous bases (A, T, C, G).

Semi-conservative and Antiparallel

Semi-conservative: Each new DNA molecule consists of one original strand and one new strand.
Antiparallel: DNA strands run in opposite directions (5' to 3' and 3' to 5').

Acids, Bases, and pH

pH: Measures the concentration of hydrogen ions (H⁺). Lower pH = more acidic; higher pH = more basic; pH 7 = neutral.
Ions: Concentration of H⁺ ions determines the acidity or basicity of a solution.

Buffers

Buffers: Substances that resist changes in pH. They are important in maintaining a stable internal environment in living organisms.

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Description

Discover the essential concepts of atomic structure, subatomic particles, isotopes, and bonds in chemistry. This quiz explores the definitions and differences between elements, compounds, and various types of bonds that hold matter together. Test your understanding of these foundational topics in chemical science.