Unit 1 Biochemistry

Hydroxyl Group

A functional group consisting of an oxygen atom bonded to a hydrogen atom (-OH), characteristic of alcohols.

Phosphate Group

A functional group consisting of a phosphorus atom double-bonded to one oxygen atom and bonded to three other oxygen atoms, involved in energy transfer.

Thiol Group

A functional group containing a sulfur atom bonded to a hydrogen atom (-SH), characteristic of mercaptans.

Amino Functional Group

A functional group consisting of a nitrogen atom bonded to two hydrogen atoms (-NH2), characteristic of amines.

Carboxyl Functional Group

A functional group consisting of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group (-COOH), characteristic of carboxylic acids.

Carbonyl Functional Group

A functional group composed of a carbon atom double-bonded to an oxygen atom (C=O), found in aldehydes and ketones.

Polar Molecule

A molecule with an uneven distribution of charge, leading to regions of partial positive and negative charges.

Nonpolar Molecule

A molecule in which electrons are shared equally, resulting in a symmetrical distribution of charge.

Polymer

A large molecule composed of repeating structural units (monomers), such as carbohydrates and proteins.

Condensation Reaction

A chemical reaction in which two molecules combine to form a larger molecule with the loss of a small molecule, usually water.

Hydrolysis Reaction

A chemical reaction that involves the breakdown of a compound by addition of water.

Carbohydrates

Biological macromolecules consisting of carbon, hydrogen, and oxygen, used for energy and structure.

Monosaccharide

The simplest form of carbohydrates, consisting of single sugar molecules, e.g., glucose.

Disaccharide

Carbohydrates formed from two monosaccharides, e.g., sucrose.

Polysaccharide

Carbohydrates composed of many monosaccharides linked together, e.g., starch and cellulose.

Glycosidic Linkage

The bond formed between monosaccharides in carbohydrates.

Plant energy storage and support (carbs)

Energy stored as starch. Support is cellulose, helping with physical stability of plants

Animal energy storage and support (carbs)

Energy stored as glycogen. Support found as chitin; hard substance/shell in bugs (exoskeleton)

Lipids

A diverse group of hydrophobic organic compounds, including fats and oils, important for energy storage and cell structure.

Saturated Fatty Acid

A fatty acid with no double bonds between carbon atoms; solid at room temperature.

Unsaturated Fatty Acid

A fatty acid containing one or more double bonds, liquid at room temperature.

Phospholipid

A lipid molecule with a hydrophilic head and two hydrophobic tails, essential for cell membrane structure.

Steroids

4 hydrocarbon rings, chemical messengers. i.e. cholesterol, estrogen

Waxes

Fatty acids and alcohols OR C rings, hydrophobic (firm but pliable), conserves water

Ester Linkage

The bonds made between lipids

Protein Structure: Primary

The unique sequence of amino acids in a polypeptide chain.

Protein structure: Secondary

Coils and folds as amino acids are added, folds into a-Helix or a-Pleated sheet

Protein structure: Tertiary

Supercoiling of polypeptide chain

Protein structure: Quaternary

2 or more polypeptide chains (coils) coming together

Enzyme

Proteins, regulate cellular activity, approx 4000 enzymes in a cell

Active Site

The specific region of an enzyme where substrate molecules bind and undergo a chemical reaction.

Enzyme Inhibitor

A substance that decreases enzyme activity; can be competitive or non-competitive.

Factors affecting enzyme activity

Température, pH, enzyme concentration, substrate concentration

Polypeptide Linkage

Bonds made between proteins

Organelles: Nucleus

Contains DNA, controls cell activity

Organelles: Mitochondria

Powerhouse of the cell, produces ATP by cellular respiration

Organelles: Ribosomes

Protein synthesis (found in cytoplasm or attached to rough ER)

Organelles: Rough Endoplasmic Reticulum

Studded with ribosomes, involved in protein synthesis

Organelles: Smooth Endoplasmic Reticulum

No ribosomes, synthesizes lipids and detoxifies

Organelles: Golgi Body

Modifies, sorts, packages proteins and lipids

Organelles: Lysosomes (ANIMAL)

Contains digestive enzymes to break down waste

Organelles: Vacuoles

Storage; large central vacuole in plants stores water. Smaller sporadic vacuoles in animals

Organelles: Chloroplasts (PLANT)

Where photosynthesis occurs

Organelles: Cell wall (PLANT)

Provides structure and support

Cell Membrane

Phospholipid bilayers that separates and protects the interior of a cell from the external environment.

Integral proteins

Spam the membrane, involved in transport

Peripheral proteins

Attached to the membrane surface, used in signalling and support

Active Transport

The process of moving molecules across a cell membrane against their concentration gradient, requiring energy.

Passive Transport

The movement of molecules across a cell membrane without the use of energy, following the concentration gradient.

Diffusion

The process of molecules spreading from areas of high concentration to areas of low concentration.

Facilitated diffusion

Uses transport proteins (channel/carrier) for larger or charged molecules

Osmosis: Hypotonic

Water moves into the cell. lower concentration outside of the cell

Osmosis: Hypertonic

Water exits cell. Concentration is higher outside of cell

Osmosis: Isotonic

Water moves freely and equally in and out of cell. Concentration is equal

Channel proteins

Provide open passageway for molecules

Carrier proteins

Bind to molecules, change shape, and transport them across

Endocytosis

The process by which cells engulf material from the outside environment, including pinocytosis and phagocytosis.

Pinocytosis (part of endocystosis)

Cell drinking fluids

Phagocytosis (part of endocytosis)

Cell eating (large particles)

Receptor-mediated (part of endocytosis)

Specific molecules bind to receptors before being taken in

Exocytosis

Expelling materials from the cell (i.e. releasing hormones or waste)

Independent Variable

The variable that is changed or controlled in an experiment to test its effects on the dependent variable.

Dependent Variable

The variable that is measured or tested in an experiment.

Control Variables

Factors that are kept constant to ensure that any changes in the dependent variable are due to the independent variable.

Biuret’s test

Tests for proteins (turns dark purple)

Lugol’s Iodine test

Tests for starch (turns dark blue/black)

Benedict’s test

Tests for simple sugars (turns green/yellow, or red depending on sugar concentration)

Sudan’s IV test

Tests for lipids (stains lipids red)