Chem of life

What are the three subatomic particles and their significance?

Protons (+1 charge, in nucleus, determine element), Neutrons (0 charge, in nucleus, create isotopes), Electrons (-1 charge, outside nucleus, control bonding).

What types of chemical bonds exist and how do they form?

Covalent (sharing electrons), Ionic (transfer of electrons), Hydrogen (attraction between polar molecules), Van der Waals (weak transient connections).

How does hydrogen bonding influence the properties of water?

It leads to cohesion, adhesion, high specific heat, less density as ice, and makes water a universal solvent.

What is the pH scale and why is it important?

0 (acidic) to 14 (basic); it measures the acidity and affects biochemical reactions.

How do buffers function in biological systems?

Buffers minimize pH changes by accepting/donating H⁺ ions.

What elements make up 96% of living matter?

Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N).

What is the basic structure of an atom?

Atoms consist of a nucleus with protons and neutrons, and electrons in shells around the nucleus.

What distinguishes isotopes?

Isotopes have the same number of protons but different numbers of neutrons, affecting atomic mass.

What is a covalent bond?

A bond where two atoms share valence electrons.

What is the difference between polar and nonpolar covalent bonds?

Polar bonds have unequal sharing of electrons, leading to partial charges; nonpolar bonds involve equal sharing.

What is an ionic bond?

An attraction between oppositely charged ions due to electron transfer.

Describe a hydrogen bond.

A weak interaction between a partial positive hydrogen atom and a strongly electronegative atom.

How many hydrogen bonds can a single water molecule form?

A single water molecule can form up to four hydrogen bonds.

What is cohesion in the context of water?

Cohesion is the linking of like water molecules, contributing to surface tension.

What is adhesion?

Adhesion is the clinging of water to other substances.

What is transpiration?

The movement of water molecules up the xylem in plants through cohesion and adhesion.

What is specific heat?

Specific heat is the amount of heat required to change a substance's temperature by 1°C.

Why is water's high specific heat important?

It stabilizes temperatures in organisms and environments.

Why does ice float on water?

Ice is less dense than liquid water due to its crystalline structure.

What is a solvent?

The substance that dissolves solutes; water is a universal solvent.

What substances are hydrophilic?

Ionic compounds and polar molecules that dissolve in water.

What substances are hydrophobic?

Nonpolar substances, like oils, that do not dissolve in water.

What does a pH below 7 indicate?

Acidity, with an excess of H⁺ ions.

What does a pH above 7 indicate?

Alkalinity, with an excess of OH⁻ ions.

What is pure water's pH?

Neutral, which is a pH of 7.0.

What is carbon's unique property that makes it essential for life?

Carbon can form four covalent bonds, allowing for a vast diversity of molecules.

What are the four main types of macromolecules in living organisms?

Carbohydrates, lipids, proteins, and nucleic acids.

What is dehydration synthesis?

A process where monomers are linked to form polymers by removing a water molecule.

What is hydrolysis?

The process of breaking down polymers into monomers by adding water.

What are monosaccharides?

The simplest form of carbohydrates, like glucose and fructose.

What distinguishes polysaccharides?

Polysaccharides are polymers made of monosaccharides, such as starch and cellulose.

What are the two main functions of polysaccharides?

Energy storage and structural support.

What makes starch and glycogen important?

They are storage polysaccharides in plants and animals, respectively.

What role does cellulose play in plants?

It provides structural support in plant cell walls.

What are lipids?

Hydrophobic molecules including fats, oils, and steroids.

What are the two types of fatty acids?

Saturated (no double bonds) and unsaturated (one or more double bonds).

What is a triglyceride?

A lipid made up of one glycerol and three fatty acids.

How do phospholipids form cell membranes?

They arrange in a bilayer with hydrophilic heads facing outward and hydrophobic tails inward.

What is the structure of an amino acid?

Central carbon attached to an amino group, carboxyl group, hydrogen, and R group.

What is a peptide bond?

A bond formed between the amino and carboxyl groups of adjacent amino acids.

What are the four levels of protein structure?

Primary (amino acid sequence), Secondary (alpha helices & beta sheets), Tertiary (3D shape), Quaternary (multiple polypeptides).

What causes protein denaturation?

Heat, pH changes, or other disturbances that disrupt the protein's structure.

What nucleic acids store genetic information?

DNA and RNA.

What is a nucleotide composed of?

Nitrogenous base, pentose sugar, and phosphate group.

What describes the structure of DNA?

Double-stranded helix with complementary base pairing (A-T, C-G).

What describes the structure of RNA?

Single-stranded, with uracil replacing thymine.

Why is polymer directionality important?

It affects the polymer's function, such as DNA's 5' to 3' orientation.

What are examples of organic compounds?

Sugars, starches, lipids, proteins, and nucleic acids.

How does changing a molecule's structure affect its function?

Altering structure can change or completely disrupt its function.

What are key roles of proteins in organisms?

They function as enzymes, transporters, structural components, and in antibody production.

Identify two important properties of lipids.

They store energy effectively and form essential cellular membranes.

Why is temperature moderation important in biology?

It supports life by maintaining stable conditions in organisms and environments.

What is the role of hydrophilic and hydrophobic substances in biological systems?

Hydrophilic substances participate in chemical reactions in an aqueous environment, while hydrophobic substances protect cellular structures.

Define functional groups in organic molecules.

Functional groups attach to carbon skeletons, influencing the behavior and properties of organic molecules.

What is the impact of R group interactions in proteins?

They determine protein folding and functionality.

Describe the significance of directionality in nucleic acids.

It affects the sequence of nucleotides, crucial for DNA replication and RNA transcription.

Give an example of a buffer in biological systems.

Bicarbonate buffer system in the blood.

What's the link between structure and function in macromolecules?

Changes in structure lead to changes in how they perform their biological roles.

How are the properties of water vital for supporting life?

Water's unique properties promote chemical reactions, stabilize temperatures, and enable nutrient transport.