M1 - Chapter 2 (Chemistry of Life)

How do we or scientists define life?

By the 5 Properties

What are the 5 basic properties that define an organism as alive?

Grow, reproduce, maintain homeostasis, sense/respond to stimuli, and obtain/use energy.

Property of Life: Grow

Getting bigger (cell size) or adding more cells

Properties of Life: Reproduce

Producing new, similar organisms

Properties of Life: Maintain Homeostasis

Keeping a stable, constant internal environment

Properties of Life: Sense/Respond to Stimuli

Reacting to changes in the environment

Properties of Life: Obtain/Use Energy

Taking in energy to power cellular work

Matter

Anything that takes up space and has mass

What is Matter made out of?

Elements

What are Elements?

Substances that cannot be chemically broken down

What is an Atom?

The smallest unit of an element that still retains the property of that element.

What is a Nucleus?

The dense core of an Atom that holds Protons and Neutrons

Homeostasis

The maintenance of a relatively constant internal environment.

Stimuli

Events in the environment that invoke a response.

Protons (Charge & Location)

Positively charged (+); located in the nucleus

Neutrons (Charge & Location)

Neutral / uncharged ; located in the nucleus

Electron (Charge & Location)

Negatively charged (-); orbits the nucleus in shells

Atomic Number

The number of protons in an atom's nucleus, which determines its identity.

Covalent Bonds

A strong chemical bond formed when two atoms share a pair of electrons

Organic Molecules

A molecule with a carbon-based backbone and at least one C–H bond.

Inorganic Molecule

A molecule that lacks a carbon-based backbone and C–H bonds.

Macromolecules

Large organic molecules composed of subunits called monomers.

Monomer

A single chemical subunit; the individual building block of a polymer.

Polymer

A large molecule made of repeating monomer subunits linked in a chain.

Carbohydrates

Macromolecules made of repeating simple sugar monomers that provide energy.

Proteins

Folded polymers made of repeating units of amino acids.

Lipids

Hydrophobic molecules that do not mix with water and are not made of repeating monomers.

Nucleic Acids

Polymers made of repeating nucleotide subunits, such as DNA and RNA.

Cell Membrane

A double layer (bilayer) of phospholipids that separates the cell from its environment.

Phospholipid Bilayer

A membrane barrier with hydrophilic (water-loving) heads facing out and hydrophobic (water-fearing) tails pointing in.

Polar Molecule

A molecule with unequally shared electrons, creating partial positive and negative charges.

Hydrogen Bond

A weak electrical attraction between a partially positive hydrogen atom and another polar molecule.

Cohesion

Water molecules clinging to each other.

Adhesion

Water molecules clinging to other surfaces.

Solvent

A substance (usually a liquid) in which another substance dissolves.

Solute

A substance that is dissolved in a solvent.

Solution

The final mixture of a solute dissolved in a solvent.

Ionic Bond

A strong chemical bond formed between oppositely charged ions.

Ion

A charged atom due to the loss or gain of an electron.

pH

A measure of the concentration of hydrogen ions (H+) in a solution.

Acid

A substance that increases the hydrogen ion (H+) concentration, resulting in a pH below 7.

Base

A substance that reduces the hydrogen ion (H+) concentration, resulting in a pH above 7.

How is the Periodic Table organized?

By Atomic Numbers

How many atoms can Carbon Atoms bond up to?

Four Atoms