asic Chemistry and Cell Biology: Elements, Bonds, and Transport Save Groups

Element

A chemical that cannot be broken down into any other substance.

Example of an element

Hydrogen, Oxygen, Nitrogen, Carbon.

Atom

The smallest unit of an element.

Nucleus of the atom

Made up of protons and neutrons.

Atomic mass of an atom

The sum of the protons and neutrons.

Atomic number of Carbon

Six, referring to the number of protons carbon has.

Atomic number

Number of protons in the atom's nucleus.

Atomic mass/weight

Weight of the atom.

Radioisotopes

Unstable isotopes that spontaneously release high-energy particles.

Half-life

The time it takes for a radioactive isotope to decrease by half.

Carbon-14 half-life

Approximately 5,730 years.

Carbon-13 and Carbon-14

Examples of isotopes of carbon that differ in atomic mass due to the number of neutrons.

First electron shell capacity

Can hold 2 electrons.

Second electron shell capacity

Can hold 8 electrons.

Third electron shell capacity

Can hold 8 electrons in its lower subshell and up to a total of 18 electrons.

Octet Rule

Atoms are most stable when their outermost electron shell is filled to capacity.

Ions

Charged atoms that have extra or missing electrons relative to the number of protons.

Big 4 elements in the human body

Oxygen, Carbon, Hydrogen, Nitrogen.

Stability of atoms

Atoms are stable when their outermost electron shell is full, allowing them to bond and form compounds.

Molecule

A group of atoms held together by bonds.

Ionic Bond

A bond formed between two oppositely charged atoms.

Example of Ionic Bond

Table salt (NaCl).

Covalent Bond

A bond created by atoms sharing electrons.

Hydrogen Bonds

Bonds that hold molecules together, occurring in polar molecules.

Polar Molecules

Molecules that have positive and negative ends.

Weaker Bond

The resulting bond from hydrogen bonding is weaker than covalent or ionic bonds.

Surface Tension

A water bug is able to 'walk' on water due to surface tension.

Ice Density

Ice floats on water because ice is less dense than water due to hydrogen bonding.

pH Scale

Measures acid to base.

Acidic Fluid

A fluid with a pH between 0 and 6.9 is considered acidic.

Basic Fluid

A fluid with a pH between 7.1 and 14 is considered basic.

Buffer Solution

A mixture that contains a weak acid and its conjugate base (or a weak base and its conjugate acid) that resists changes in pH.

Antacids

A form of buffer that treats acid reflux and neutralizes hydrogen atoms.

Solution

A mixture of molecules, consisting of a solvent and a solute.

Concentration Gradient

The relationship between the concentrations of solutes inside the cell and the solutes outside the cell.

Passive Transport

Movement that does not require energy on the part of the cell.

Diffusion

The spontaneous movement of a substance across the plasma membrane from higher to lower concentration.

Osmosis

The passive diffusion of water across a membrane.

Active Transport

Movement that requires energy.

Influence of Other Molecules in Osmosis

Osmosis is influenced by the concentration of other molecules inside or outside the cell that are unable to move across the membrane.

Water Movement in Osmosis

During osmosis, water flows from areas of high solute concentration to areas of low solute concentration.

Effect of Freshwater on Cells

When cells are placed in freshwater, water will enter the cells through the cell membrane.

Animal Cells in Freshwater

Animal cells will burst due to their lack of a rigid cell wall.

Plant Cells in Freshwater

Plant cells become turgid and firm as the cell wall resists the internal pressure.

Energy Source for Active Transport

Active transport can use ATP energy in order to move large molecules or to move substances against their concentration gradients.

Membrane Proteins in Active Transport

Active transport may use membrane proteins to help 'pump' molecules across the membrane.

Proton Pumps

The proton pumps in your stomach are examples of active transport.

Primary Active Transport

Primary active transport because they directly use the energy from ATP hydrolysis to move hydrogen ions (protons) against their concentration gradient into the stomach.

Organic Molecules

A large, complex carbon-based molecule that contains carbon-hydrogen bonds and often includes other elements like oxygen, nitrogen, and sulfur.

Definition of Macromolecule

A large, complex carbon-based molecule that contains carbon-hydrogen bonds and often includes other elements like oxygen, nitrogen, and sulfur.

Types of Macromolecules

The four major types of macromolecules that are necessary for our cells include: Carbohydrates, Proteins, Lipids, Nucleic acid.

Polymers

Many subunits joined together by some bond.

Monomers

One unit.

Synthesis

Synthesis (also known as dehydration synthesis) creates macromolecules.

Hydrolysis

Hydrolysis (also known as condensation reaction) breaks down macromolecules.

Carbohydrates

Carbohydrates are made up of monomers.

Monosaccharides

Monosaccharides are also called simple sugars. Examples: fructose and glucose.

Function of Carbohydrates

To provide energy.

Glucose

Glucose provides energy for the body's cells.

Complex Carbohydrates

Complex carbohydrates store packets of energy.

Disaccharides

Disaccharides are two monosaccharides linked together.

Polysaccharides

Polysaccharides are many monosaccharides (even thousands) linked together.

Starch

As storage of glucose.

Glycogen

As a short-term energy reserve.

Chitin

Found in exoskeletons of insects and crustaceans.

Cellulose

Found in foods humans consume.

Dietary Fiber

Acts as roughage, providing bulk for the digestive system, helping soften stools, promoting regular bowel movements, and aiding in the prevention of constipation.

Lipids

A large, diverse group of macromolecules with important functions.

Triglyceride

A type of fat molecule composed of glycerol and three fatty acids.

Saturated Fat

A type of fat that is solid at room temperature.

Unsaturated Fat

A type of fat that is liquid at room temperature.

Trans Fat

Mimics solid structure but raises bad LDL cholesterol and lowers good HDL cholesterol, making it unhealthy.

Hydrogenation

A chemical process that adds hydrogen atoms to liquid unsaturated fats, converting them into solid or semi-solid fats.

Cholesterol

Used to build sex hormones and membranes.

Phospholipids

Key structures in cell membranes, composed of a glycerol head and two fatty acid tails.

Sterols

Basic structure consists of a steroid nucleus with four fused hydrocarbon rings.

Amino Acids

Building blocks of proteins, with 20 different types available.

Essential Amino Acids

Amino acids that must be obtained through the diet.

R-group

The unique side chain attached to the central alpha carbon of an amino acid.

Hydrophilic

Molecules that interact well with water.

Hydrophobic

Molecules that lack electrical charges and do not interact well with water.

Protein Function

A protein's function is influenced by its three dimensional shape.

Peptide Bond

Cells build proteins by linking amino acids together by a peptide bond.

Amino Acid Order

The order of the amino acids, as well as the overall shape of the protein, impacts how that protein functions.

Protein Structure Levels

The structure levels of proteins are: primary, secondary, tertiary, and quaternary.

Protein Shape Alteration

If, at any time, something alters the shape of the protein, the protein will no longer be able to function properly.

Enzymes

Enzymes are proteins that speed up chemical reactions.

Enzyme Function

An enzyme can perform its job more than once.

Enzyme Shape Change Problem

If the shape of an enzyme is changed, its active site can no longer bind to its specific substrate, leading to a loss of its ability to catalyze chemical reactions.

Plasma Membrane Proteins

Protein molecules embedded in the cell's plasma membrane help it perform its functions.

Receptor Proteins

Receptor proteins are receiving proteins, initiating results.

Recognition Proteins

Recognition proteins are involved in cellular identification, immune system defense, and tissue compatibility.

Transport Proteins

Transport proteins regulate passage and include channel proteins and carrier proteins.

Membrane Enzymes

Membrane enzymes catalyze reactions, localize metabolic pathways, and regulate signals.

Nucleic Acids

Nucleic acids are macromolecules that hold the genetic information to build and maintain an organism.

Nucleotide

The building blocks of nucleic acids are nucleotides.

Nucleotide Structure

A nucleotide is made up of three parts: a phosphate group (PO4), a sugar, and a nitrogen-containing molecule called a nitrogenous base.

DNA Bases

In DNA, each nucleotide can contain one of four different bases: Adenosine, Thymine, Guanine, and Cytosine.

DNA Structure

Many nucleotides linked together create a strand of DNA, which spirals around each other, forming the structure of DNA known as deoxyribonucleic acid.

DNA Pairing

The bases in DNA always pair together in a specific manner.