Chapter 2: Comprehensive Chemistry of Life: Atoms, Bonds, Organic Compounds, and Cell Function

What is the most basic structural level of organization in living organisms?

The chemical level of organization.

What are the components that make bones strong?

Bones are composed of minerals and collagen.

Define matter in the context of chemistry.

Matter is anything that takes up space.

What is chemistry the study of?

Chemistry is the study of matter and its interactions.

What is an atom?

An atom is the smallest unit of matter.

How is an element defined?

An element is a substance composed of one or more identical atoms and cannot be broken into simpler substances.

What are protons?

Protons are positively charged particles that reside in the atomic nucleus.

What are neutrons?

Neutrons are uncharged particles that are slightly larger than protons and also located in the nucleus.

What are electrons?

Electrons are negatively charged particles that surround the nucleus of an atom.

Why are atoms considered neutral?

Atoms are neutral because the number of protons equals the number of electrons.

What are electron shells?

Regions surrounding the nucleus where electrons are found.

What is the maximum number of electrons in the 1st, 2nd, and 3rd electron shells?

1st shell: 2, 2nd shell: 8, 3rd shell: 18 (but satisfied with 8).

How is an element defined in terms of protons?

An element is defined by the number of protons in its nucleus, known as the atomic number.

What are the four major elements that make up 96% of the human body?

Oxygen (65%), Carbon (18%), Hydrogen (10%), Nitrogen (3%).

Name the seven mineral elements that make up less than 4% of the body.

Sodium, potassium, calcium, chlorine, magnesium, phosphorus, and sulfur.

What is a mass number?

The sum of all the protons and neutrons in the atomic nucleus.

What is an isotope?

An isotope is an atom that has the same number of protons but a different number of neutrons.

What are radioisotopes?

Unstable isotopes that release energy as radiation.

What is the purpose of cancer radiation therapy?

To damage and kill cancer cells.

What are radiotracers used for in nuclear medicine?

They are injected into patients and analyzed to show the size, shape, and activity of cells and organs.

What distinguishes a mixture from a molecule?

A mixture is formed by physically combining elements without changing their chemical nature, while a molecule is formed by chemically combining atoms.

What are suspensions in terms of mixtures?

Suspensions are liquids mixed with solids where large solid particles are visible and will settle out.

What are colloids?

Colloids are liquids mixed with solids where small solid particles are not visible and remain dispersed.

What defines a solution in chemistry?

A solution is a liquid (usually water) mixed with a solid, liquid, or gas.

What is a solute and solvent in a solution?

A solute is a substance that dissolves in another substance called a solvent, resulting in a translucent appearance.

What defines a chemical bond?

A chemical bond is an energy relationship or attractive force between atoms.

What is a molecule?

A molecule forms when two or more atoms of the same element are chemically bonded.

What is a compound?

A compound forms when two or more atoms of different elements are chemically bonded.

What are macromolecules?

Macromolecules are very large compounds composed of many atoms.

What is the octet rule?

The octet rule states that an atom is most stable with 8 electrons in its valence shell.

What is the duet rule?

The duet rule applies to atoms with 5 or fewer electrons, indicating they are most stable with 2 electrons in the first shell.

What are ionic bonds?

Ionic bonds are formed when electrons are transferred between a metal atom and a nonmetal atom.

What is an ion?

An ion is a charged atom that results from gaining or losing an electron.

What is a cation?

A cation is a positively charged ion.

What is an anion?

An anion is a negatively charged ion.

What holds ionic bonds together?

The attraction between oppositely charged ions holds ionic bonds together, forming compounds known as salts.

What are covalent bonds?

Covalent bonds are formed when electrons are shared between two or more nonmetal atoms, making them the strongest type of chemical bond.

What is a nonpolar covalent bond?

A nonpolar covalent bond occurs when electrons are shared equally between atoms of the same element.

What characterizes polar covalent bonds?

Polar covalent bonds involve unequal sharing of electrons, with atoms having different electronegativities.

What are dipoles in polar molecules?

Dipoles are polar molecules with partially positive and partially negative ends.

What are hydrogen bonds?

Hydrogen bonds are weak attractions between partially positive and partially negative atoms in polar covalent molecules.

What is surface tension in water?

Surface tension results from hydrogen bonds forming a 'web' of molecular connections between polar water molecules.

How can you determine if a compound is ionic?

A compound is ionic if it contains a metal and a nonmetal.

What indicates a nonpolar molecule?

A molecule is nonpolar if it contains two identical nonmetals.

What indicates a polar compound?

A compound is polar if it contains two nonmetals with different electronegativities.

What is the definition of a chemical reaction?

A chemical reaction occurs when a chemical bond is formed, broken, or rearranged, or when electrons are transferred.

What are reactants in a chemical equation?

Reactants are the starting substances that undergo a chemical reaction.

What is potential energy?

Potential energy is stored energy that is ready to be released and used to do work.

What is kinetic energy?

Kinetic energy is energy in motion.

What are catabolic reactions?

Catabolic reactions break larger substances into smaller ones and are generally exergonic.

What are anabolic reactions?

Anabolic reactions form new chemical bonds and are endergonic.

What is the role of enzymes in chemical reactions?

Enzymes increase the rate of reactions by lowering the activation energy and are highly specific for individual substrates.

What is the pH scale?

The pH scale represents the hydrogen ion concentration of a solution, with pure water being neutral at 7.

What happens to pH when more hydrogen ions are added to a solution?

The pH decreases as the concentration of hydrogen ions increases.

What does a lower pH indicate about hydrogen ion concentration?

A lower pH indicates a higher hydrogen ion concentration.

What is the relationship between changes in negative logarithm and hydrogen ion concentration?

Single-digit changes in the negative logarithm accompany a 10-fold change in hydrogen ion concentration.

What are buffers in biological systems?

Buffers are chemical systems that resist changes in pH and prevent large swings in pH when acids or bases are added.

What is the major buffer system in the human body?

The carbonic acid-bicarbonate buffer system.

What pH levels indicate acidosis and alkalosis in blood?

Acidosis occurs if blood pH falls below 7.35, and alkalosis occurs if blood pH rises above 7.45.

What is a salt in chemical terms?

A salt is any metal cation and nonmetal anion held together by ionic bonds.

What are electrolytes?

Electrolytes are the resulting cations and anions in solution when salts are dissolved in water.

What are hydrocarbons?

Hydrocarbons are organic compounds containing only carbon and hydrogen, existing as chains and rings.

What are the four main organic compounds in the body?

Carbohydrates, proteins, lipids, and nucleic acids.

What are monomers?

Monomers are single subunits that can be combined to build larger structures.

What are polymers?

Polymers are larger structures consisting of many monomers linked together.

What is dehydration synthesis?

Dehydration synthesis is the process that links two monomers by removing a molecule of water.

What is hydrolysis?

Hydrolysis is a reaction that splits a polymer by adding a molecule of water.

What is the monomer of carbohydrates?

The monomer of carbohydrates is called a monosaccharide.

What are disaccharides?

Disaccharides are carbohydrates formed by two monosaccharides linked together.

What are polysaccharides?

Polysaccharides are long branching chains of monosaccharides.

What is the primary function of carbohydrates?

Carbohydrates primarily function as energy sources and structural components.

What are glycoproteins and glycolipids?

Glycoproteins and glycolipids are specialized carbohydrates attached to proteins and lipids that help maintain cell structure and communication.

What are lipids made of?

Lipids are made of carbon, hydrogen, and some oxygen.

What is the monomer of lipids?

The monomer of lipids is called a fatty acid.

What are triglycerides?

Triglycerides are natural fats made of three fatty acids linked to a glycerol.

What are phospholipids?

Phospholipids consist of a glycerol backbone, two fatty acids, and a phosphate group, forming the main structural component of cell membranes.

What are steroids?

Steroids are lipids characterized by a four-ring hydrocarbon structure.

What are omega-3 fats?

Omega-3 fats are beneficial fats found in flaxseed oil and fish oil, known for their positive effects on cardiovascular health.

What are saturated fats?

Saturated fats are found in animal fats and certain oils, associated with increased heart disease risk.

What are trans-fats?

Trans-fats are produced by adding hydrogen to unsaturated plant oils and have no safe consumption level.

What are proteins made of?

Proteins are made of carbon, hydrogen, oxygen, nitrogen, and smaller amounts of other elements.

What are amino acids?

Amino acids are the monomers of proteins, with 21 different types.

What is protein denaturation?

Protein denaturation is the process that causes a protein to lose its shape and function due to heat, pH changes, or chemicals.

What are nucleic acids?

Nucleic acids are made of carbon, hydrogen, oxygen, nitrogen, and phosphorus, including DNA and RNA.

What is the structure of DNA?

DNA is a large polymer composed of two strands of nucleotides forming a double helix.

What is the role of ATP in cells?

ATP is the main source of chemical energy driving cellular processes.

What is the genetic code?

The genetic code is found within DNA and contains the 'recipes' for each protein in the body.