BIOL-Unit2 Chapter2 -Q&A

Flashcards created from BIOL 113 Module 2a guided notes covering basic chemistry, cell theory, chemical reactions, pH, macromolecules, protein structure, and nucleic acids.

What are the four tenets of cell theory?

a. Cells are the building blocks of all organisms. b. All cells come from the division of pre-existing cells. c. Cells are the smallest units that carry out essential physiological functions. d. Each cell maintains homeostasis at the cellular level.

Which parts of an atom are found in the nucleus?

Protons and Neutrons.

Which part of an atom moves around the nucleus?

Electrons.

What are the electrical charges of neutrons, protons, and electrons?

A neutron has a neutral charge, a proton has a $+$ charge, and an electron has a $-$ charge.

What is the order of chemical bonds from weakest to strongest?

a. Hydrogen bonds, b. Ionic bonds, c. Covalent bonds.

What happens to electrons in an ionic bond?

Electrons are transferred to another atom.

What happens to electrons in a covalent bond?

Electrons are shared between another atom.

What is the 2-8-8 rule for electron shells?

The first layer can hold $2$ electrons, while all other shells can hold $8$.

What is the outermost shell of an atom called?

Valence layer.

What is the difference between a cation and an anion?

A cation is a positively charged atom, whereas an anion is a negatively charged atom.

What is metabolism?

The sum of all chemical reactions in the body.

How do anabolism and catabolism differ?

Anabolism refers to chemical reactions that increase the size of molecules, while catabolism refers to chemical reactions that decrease the size of molecules.

How is an enzyme defined?

Enzymes are catalysts to chemical reactions that speed up chemical reactions or lower the amount of energy required for a chemical reaction to occur.

What are the four main types of chemical reactions?

a. Combination reactions (two reactants combine to form one product), b. Decomposition reactions (one reactant decomposes to form two products), c. Displacement reactions (one element displaces another element from a compound), d. Combustion reaction (a substance reacts with oxygen, usually with the rapid generation of heat to produce a flame).

What are polar covalent bonds?

Bonds where electrons are shared unequally between atoms.

What are the four unique properties of water?

a. Universal solvent (fluid in which substances can dissolve), b. Helps with chemical reactions (can help break down or build up molecules), c. High heat capacity (can handle a lot of heat without changing temperature quickly), d. Great lubricant (helps tissues and organs move smoothly without much friction).

What does the pH scale measure and what are the numerical classifications for neutral, alkaline, and acidic?

The pH scale ranges from $0$ to $14$ and measures the amount of hydrogen ions. A pH of $7$ is neutral, greater than $7$ is alkaline (basic), and lower than $7$ is acidic.

What is a buffer and why is it important?

Buffers are like sponges that take up hydrogen ions when there's too much and release them when there's too little. They are important because they prevent solutions from becoming alkaline or basic.

What is metabolic acidosis?

A state where there is an excess of hydrogen ions because the body builds up too much acid or loses too much base (bicarbonate).

What is metabolic alkalosis?

A state where the body loses too much acid and retains/returns too much base, resulting in a shift in hydrogen ion production.

What are the four major macromolecules in the human body, their examples, and primary functions?

a. Carbohydrates (sugar, starch, fiber; provides energy, excess stored as fat), b. Proteins (structural support, movement, enzymes, hormones, immune system), c. Lipids (fats; stores energy, structural components, insulation), d. Nucleic acids (DNA & RNA; store & transfer information).

All cell membranes are made of what type of lipid?

Phospholipids.

What is the difference between hydrophilic and hydrophobic substances?

Hydrophilic refers to a substance that attracts or mixes with water, whereas hydrophobic refers to a substance that does not mix with water or repels it.

What is the structure of a micelle?

$1$ glycerol + $3$ fatty acids.

What is the function of cholesterol in the cell membrane?

Stabilizes the cell membrane.

What are six functions of proteins?

a. Structural support, b. Necessary for movement, c. Transportation (e.g., hemoglobin transports oxygen), d. Acts as a buffer, e. Acts as an enzyme & hormones, f. Plays a role in the immune system.

What are the building blocks (monomers) of proteins?

Amino acids.

What are the four parts of an amino acid?

a. Amino group, b. Central Carbon, c. Carboxyl group, d. R group.

How many amino acids are in the human body?

$$20$$

What are the four structures of proteins?

a. Primary Structure (the order of amino acids), b. Secondary Structure (forms spirals or sheets), c. Tertiary Structure (forms 3D shape), d. Quaternary Structure (combines multiple polypeptides).

What are the two main types of nucleic acids?

a. DNA, b. RNA.

What are the three parts of a nucleotide?

a. Phosphate group (connects nucleotides together), b. Sugar (ribose in RNA, deoxyribose in DNA), c. Nitrogenous group (combines genetic info).

What are the four nitrogenous bases of DNA and how do they pair?

Adenine pairs with Thymine, and Guanine pairs with Cytosine.

What are the four nitrogenous bases of RNA and how do they pair?

Adenine pairs with Uracil, and Guanine pairs with Cytosine.