Chapter 2: Chemical Basis of Life Flashcards

Flashcards reviewing key concepts from Chapter 2 lecture notes, including atomic structure, chemical bonds, chemical reactions, pH and buffers, and organic macromolecules.

What neurotransmitter depletion causes Parkinson's disease, and what chemical precursor drug is used to treat it?

Parkinson's disease derives from a depletion of the neurotransmitter dopamine within the central nervous system. Treatment includes levodopa, which is a precursor to dopamine.

How is matter defined in chemistry?

Matter is defined as anything that has mass and occupies space.

What four major elements constitute $96\%$ of the human body's weight?

Oxygen, carbon, hydrogen, and nitrogen.

What percentage of total body weight do minor elements constitute, and what key examples are mentioned?

Minor elements constitute about $3\%$ or less of total body weight. Examples include calcium, potassium, sodium, and iron.

What is the specific physiological function of iron in the body?

Iron allows oxygen to bind to red blood cells.

What is the definition of a chemical compound?

A compound is a substance resulting from a chemical reaction of two or more different types of atoms.

What is the key structural difference between inorganic compounds and organic compounds?

Inorganic compounds do not contain both carbon and hydrogen in their chemical makeup, whereas organic compounds contain both carbon and hydrogen.

What are the textbook examples for an inorganic compound and an organic compound?

Water ($H_2O$) is an inorganic compound, while glucose ($C_6H_{12}O_6$) is an organic compound.

What are the three subatomic particles of an atom and their respective charges?

Neutrons have no charge (neutral), protons have a positive charge, and electrons have a negative charge.

What are the maximum electron capacities of an atom's innermost shell and its subsequent outer shells?

The innermost electron shell has a maximum capacity of $2$ electrons, while each subsequent outer ring has a maximum capacity of $8$ electrons.

How does an atom become an ion?

An atom becomes an ion when an electron is gained or donated, breaking the equal balance between protons and electrons and producing a positive or negative charge.

What is the definition of electronegativity?

Electronegativity is the ability of an atom's nucleus to pull an electron towards it.

What is the difference between a cation and an anion?

A cation is a positively charged ion with more protons than electrons, whereas an anion is a negatively charged ion with more electrons than protons.

What are the three types of chemical bonds discussed, in order from weakest to strongest?

Ionic bonding is the weakest, polar covalent bonding is intermediate, and nonpolar covalent bonding is the strongest.

Why do ionic bonds disassociate easily when placed in water?

In water, the positively charged ions are attracted to the negative ends of water molecules, and the negatively charged ions are attracted to the positive ends of water molecules, causing them to separate.

What characterizes a polar covalent bond?

A polar covalent bond occurs between two atoms with different electronegativities, leading to an unequal sharing of electrons and an uneven (asymmetric) distribution of charge.

What is the difference between reactants and products in a chemical reaction?

Reactants are substances that enter into a chemical reaction, while products are substances that result from a chemical reaction.

What are synthesis and decomposition reactions, and what are their collective terms?

Synthesis reactions combine two or more reactants to form a larger product (collectively called anabolism). Decomposition reactions break down larger products into smaller units (collectively called catabolism).

How is metabolism defined?

Metabolism is defined as the combination of all anabolic (synthesis) and catabolic (decomposition) reactions within the body.

What are the four types of energy described in the lecture?

Potential energy (stored energy), kinetic energy (energy of object movement), mechanical energy (energy resulting from position/movement of objects or limbs), and chemical energy (potential energy stored within chemical bonds).

What are catalysts and enzymes?

Catalysts are agents that increase the rate of a chemical reaction. Enzymes are protein catalysts that specifically increase the rate of chemical reactions in the body.

How are acidic, neutral, and basic/alkaline solutions defined on the pH scale?

A pH of $7.0$ (distilled water) is neutral. A pH less than $7.0$ is acidic, while a pH greater than $7.0$ is alkaline or basic.

How are acids and bases defined with respect to protons (hydrogen ions)?

An acid is a proton donor (releases hydrogen ions in water). A base is a proton acceptor (such as hydroxide ions binding with hydrogen ions).

What is the normal pH range for human blood?

The normal pH range for human blood is $7.35$ to $7.45$.

What is a chemical buffer?

A buffer is a chemical that resists changes in pH when either an acid or a base is added to a solution.

What is the difference between hydrophilic and hydrophobic molecules?

Hydrophilic molecules are attracted to water, whereas hydrophobic molecules are repelled by water.

What are the three levels of carbohydrate complexity and their examples?

Polysaccharides (e.g., glycogen, starch, cellulose), disaccharides (e.g., sucrose, maltose, lactose), and monosaccharides (e.g., glucose, fructose, galactose).

What is cellular respiration?

Cellular respiration is a set of metabolic pathways through which humans convert glucose to ATP to make energy.

What are the three types of lipids and their functions?

Triglycerides (energy storage in adipose tissue), steroids (cholesterol used to synthesize hormones like estrogen, progesterone, and testosterone), and phospholipids (structural components of cell membranes).

What are amino acids, and what defines an 'essential' protein?

Amino acids are the building blocks of all proteins. Out of $20$ types, the human body can synthesize $12$; the remaining $8$ cannot be synthesized by the body and are called essential proteins because they must be obtained through the diet.

Which nitrogenous bases are unique to DNA and RNA?

Thymine is present only in DNA, while uracil is present only in RNA. Cytosine, adenine, and guanine are found in both.

How does ATP release energy for cellular work?

ATP (adenosine triphosphate) releases chemical energy when a phosphate group is broken off, converting ATP into ADP (adenosine diphosphate) and a free phosphate.