B) LECTURE CH2 CARDS

Chemical Reaction

A process where chemical bonds are broken or formed, changing substances into new substances.

Example: Digestion uses chemical reactions to break food into smaller parts.

Valence Shell

The outermost electron shell of an atom.

Chemical Bond

A force that holds atoms together.

Metabolism

All the chemical reactions happening in the body. Example: Breaking down food for energy is part of metabolism.

Law of Conservation of Energy

Energy cannot be created or destroyed. It can only change from one form to another.

Example: Chemical energy in food can be changed into energy the body can use.

Reactants

The starting substances in a chemical reaction.

Products

The substances made by a chemical reaction.

Inorganic Compounds

Simple compounds that usually do not contain carbon.

Organic Compounds

Compounds that contain carbon and are often large and complex. They usually also contain hydrogen.

Carbon

An element found in all organic compounds. Carbon can bond with many other atoms.

Hydrogen (where is it commonly found)

An element commonly found in organic compounds.

Covalent Bond

A chemical bond where atoms share electrons.

Water

The most common inorganic compound in the body. Water is polar and is a good solvent for many substances. Water is also removed during dehydration synthesis and added during hydrolysis.

Polarity

An uneven sharing of electrons that gives a molecule slightly positive and slightly negative areas.

Valence Electrons

Electrons in the outermost shell of an atom that take part in chemical bonding.

Acid

A substance that releases hydrogen ions, or H+, in solution. Acids have a pH below 7.

Base

A substance that accepts hydrogen ions or can release hydroxide ions, OH−, in solution. Bases have a pH above 7.

Hydrogen Ion, H+

A positively charged hydrogen ion. More H+ makes a solution more acidic and lowers PH

Hydroxide Ion, OH−

A negatively charged ion made of oxygen and hydrogen. More OH− makes a solution more basic.

Salt

A compound that separates into positive and negative ions in water but does not act as an acid or base.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Dissociation

When a compound separates into ions after dissolving in water.

pH

A measure of the amount of H+ in a solution and how acidic or basic the solution is.

pH Scale

A scale from 0 to 14 used to measure acidity and basicity. Below 7 is acidic, 7 is neutral, and above 7 is basic. Each whole number change represents a tenfold change in H+ concentration.

Acidic

A solution with a pH below 7 and more H+ than OH−.

Basic or Alkaline

A solution with a pH above 7 and less H+ than an acidic solution.

Neutral

A solution with a pH of 7 where H+ and OH− are balanced.

Buffer or Buffer System

A substance or system that helps prevent large changes in pH by taking up or releasing hydrogen ions. Buffers commonly involve a weak acid and weak base.

Weak Acid

An acid that releases only some of its hydrogen ions in water.

Weak Base

A base that can take up hydrogen ions and help reduce changes in pH.

Bicarbonate, HCO3−

A weak base that helps control blood pH by taking up extra hydrogen ions.

Bicarbonate Buffer System

The major buffer system in the blood. It uses carbonic acid and bicarbonate to resist large changes in pH.

Carbohydrates

Organic molecules that provide energy, help provide building materials, and can store energy for later.

Carbohydrate Function 1: Energy

Carbohydrates provide much of the body's usable energy.

Carbohydrate Function 2: Building Materials

Some carbohydrates are changed into other substances that the body uses to build structures.

Carbohydrate Function 3: Energy Storage

Some carbohydrates are stored as an energy reserve. Example: Humans store carbohydrate energy mainly as glycogen.

what is ATP? and what does it contain? when does the energy get released?

ATP is the main molecule cells use to transfer usable energy. It contains adenine, ribose, and three phosphate groups. Energy is released when the last phosphate is removed.

Monosaccharide

The simplest type of carbohydrate. It is one sugar unit and is the basic building block of larger carbohydrates. Examples: Glucose, fructose, galactose, ribose, and deoxyribose.

Disaccharide

A carbohydrate made from two monosaccharides joined together.

Polysaccharide

A large carbohydrate made from many monosaccharides joined together.

Pentose

A sugar containing five carbon atoms.

Hexose

A sugar containing six carbon atoms. Example: Glucose, fructose, and galactose are hexose sugars.

Ribose

A five carbon sugar found in RNA. Example: Ribose is part of RNA nucleotides.

Deoxyribose

A five carbon sugar found in DNA. Example: Deoxyribose is part of DNA nucleotides.

Glucose

A six carbon monosaccharide that is a major source of energy for cells. Example: Cells break down glucose to help make ATP.

Fructose

A six carbon monosaccharide commonly found in fruit. Example: Fructose can join with glucose to make sucrose.

Galactose

A six carbon monosaccharide that can combine with glucose. Example: Galactose joins with glucose to make lactose.

Nucleic Acids

Organic molecules that include DNA and RNA and store or use genetic information.

Dehydration Synthesis

A reaction that joins smaller molecules together by removing water.

Disaccharides are made by combining 2

monosaccharides by removing a water

molecule

Hydrolysis

A reaction that uses water to break a larger molecule into smaller molecules.

Sucrose

A disaccharide glucose + fructose.

Lactose

A disaccharide glucose + galactose.

Dehydration vs Hydrolysis

Dehydration synthesis removes water and builds larger molecules. Hydrolysis adds water and breaks larger molecules apart.

Buffers and Strong Acids or Bases

Buffers help reduce the effects of strong acids and bases so pH does not move too far.

Three Main Functions of Carbohydrates

Carbohydrates provide energy, provide building materials, and store energy.

what does Glycogen do? And what is it made out of? is it a polysaccaride or a monosaccaride?

The main storage form of carbohydrate in the human body. It is a polysaccharide made from many glucose units and is stored mainly in the liver and skeletal muscles.

Starch

A polysaccharide used by plants to store glucose.

Lipids

A major group of organic molecules that includes fats. Most lipids do not mix well with water.

Why Are Most Lipids Not Soluble in Water?

Most lipids are nonpolar while water is polar. Because of this they do not mix well.

Unsaturated Fat

A fatty acid with one or more carbon to carbon double bonds. The double bond can cause a bend in the fatty acid chain.

Saturated vs Unsaturated Fat

Saturated fatty acids have no carbon to carbon double bonds. Unsaturated fatty acids have one or more carbon to carbon double bonds.

Phospholipid

A lipid with one polar water loving head and two nonpolar water avoiding fatty acid tails. Phospholipids form cell membranes because the heads interact with water while the tails point away from water.

Amino Acid

The building block or monomer of proteins. There are 20 amino acids. They share the same basic structure but each has a different R group that controls its chemical behavior.

Peptide Bond

A covalent bond that joins two amino acids together. It forms during dehydration synthesis.

Four Levels of Protein Structure

Proteins have four levels of structure: primary, secondary, tertiary, and quaternary. These levels determine the protein's final shape and function.

Protein Shape

A protein's shape depends mainly on its amino acid sequence and interactions between amino acid R groups. Shape is important because it determines what the protein can do.

Denaturation

The loss of a protein's normal shape causing it to lose its function. Heat, changes in pH, or other harsh conditions can cause denaturation.

Example: Heating egg white changes the shape of its proteins.

Nucleotide

The monomer of nucleic acids. A nucleotide has three parts: a phosphate group, a five carbon sugar, and a nitrogenous base.

DNA vs RNA

DNA is usually double stranded, contains deoxyribose sugar, and uses thymine.

RNA is usually single stranded, contains ribose sugar, and uses uracil.

Proteins

Large organic molecules made from amino acids. Their shape helps determine their function.

Six major functions are structure, movement, transport, defense, regulation, and acting as enzymes.