Biology 1 chapter 6 Chemistry in Biology

Catalyst

All living things are chemical factories driven by chemical reactions. To be useful to living organisms, additional substances must be present where chemical reactions occur to reduce the activation energy and allow the reaction to proceed quickly. A catalyst is a substance that lowers the activation energy needed to start a chemical reaction.

Matter

Anything that has mass and takes up space. All organisms are made up of matter.

Colloid

a type of heterogeneous mixture in which the particles do not settle out like the sand settled from the water. Ex: fog, smoke, butter, mayonnaise, milk, paint, ink and blood.

Suspension

a type of heterogeneous mixture that over time the particles settle out at the bottom. Ex: sand and water

Hydrogen bonds

a weak interaction involving a hydrogen atom and a fluorine, oxygen, or nitrogen atom. Hydrogen bonding is a strong type of van der Waals interaction.

Covalent bonds

chemical bonds formed atoms share electrons in their outer energy shell. most compounds in living organisms have covalent bonds holding them together.

Chemical equations

chemical equations express each component of a chemical reaction. when writing chemical equations, chemical formulas describe the substances in the reaction and arrows indicate the process of change.

Exothermic

chemical reaction that releases energy or heat. (read pg. 158)

Endothermic

chemical reaction that stores or absorbes energy

Nucleic acids

complex macro-molecules that store and transmit genetic information. DNA ( deoxyribonucleic acid) and RNA (ribonucleic acid)

Molecule

compound by which the atoms are held together by covalent bonds

Characteristics of Compounds

compounds are always formed in a specific combinations of elements in a fixed ration, compounds are physically different than the elements that comprise them, and compounds cannot be broken down into simpler compounds or elements by physical means but they can be broken down by chemical means.

Carbohydrates

compounds composed of carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom. CH2O

Organic compounds

compounds containing carbon. Ex: carbohydrates (sugars), proteins, lipids (fats), nucleic acids

Amino Acids

has a central carbon atom bond to a hydrogen atom. the other three bonds are with an amino group (-NH2, a carboxyl group (-COOH), and a variable group (-R). the R group makes each amino acid different. there are 20 different amino acids in nature.

Balanced equations

in chemical reactions, matter cannot be created or destroyed. all chemical equations must be balanced. what goes into an equation, must come out of it.

Steroids

includes substances such as cholesterol and hormones. despite its bad reputation as a bad lipid, cholesterol provides the starting point for other necessary lipids such as vitamin D and hormones estrogen and testosterone.

Macromolecules

large molecules that are formed by joining small molecules together. Ex: starch is a long chain of glucose, proteins are long chains of amino acids.

ATP (adenosine triphosphate)

nucleotide with 3 phosphate groups. ATP is a storehouse of chemical energy that can be used by cells in a variety of reactions.

Neutrons

particles found inside the nucleus of an atom that have no charge or they are neutral

Protons

positively charged particles found inside the nucleus of an atom

Phospholipids

responsible for the structure and function of cell membrane. lipids are hydrophobic which means they don't dissolve in water, this allows lipids to serve as barriers in biological membranes.

Nucleotides

small monomers that make up nucleic acids. nucleotide are composed of C, N, O, P, and H atoms. 6 major nucleotides composed of a phosphate, a nitrogenous base, and ribose sugar.

Common ions in living organisms

sodium (Na+), potassium (K+), calcium (Ca++), chloride (Cl-), hydrogen (H+), and carbonate ions (CO3--)

Two components of a solution: solvent and solute

solvent-substance in which another substance is dissolved. ex-water. solute-substance that is dissolved in the solvent. exs-salt water, air, and saliva

Acids

substances that release H+ when dissolved in water. When a substance that contains H+ is dissolved in water, the substance might release a H+ because it is attracted to the negatively charged Oxygen atoms in water.

Bases

substances the release OH- (hydroxide ions) when dissolved in water. Ex: NaOH when dissolved in water releases Na+ and OH-

Atoms

the building blocks of matter

Nucleus

the center of an atom

Heterogeneous mixtures

the components remain distinct, that is you can tell what they are individually. Ex: sand and water.

Chemical bonds

the force that holds the substances in compounds together. it is t he forming of chemical bonds that stores energy and the breaking of chemical bonds that provides energy for processes of growth, development, adaptation, and reproduction of living things.

Energy of reactions

the key to starting a chemical reaction is energy. most compounds in living things cannot undergo chemical reactions without energy.

Reactants and products

A chemical equations shows the reactants, the starting substances, on the left side of the arrow and the products, the substances formed on the right side of the arrow. The arrow can be read as "yields" or "react to form".

Carbon (C) atomic number 6

Carbon has four electrons in its outermost energy level, but it can hold up to eight. Therefore, carbon will form 4 covalent bonds with other atoms. These covalent bonds enable he carbon atoms to bond with each other to produce a variety of important organic molecules.

How an enzyme works (substrates and active sites)

Reactants that bind to enzymes are called substrates. The specific location where a substrate binds on an enzyme is called an active site. The substrate and active site fit together like a puzzle to form the enzyme-substrate complex. The enzyme-substrate complex helps chemical bonds in the reactants to be broken and new bonds to form-the substrates react to form products. The enzyme then releases the products.

Activation energy

The minimum amount of energy needed for reactants to form products in a chemical reaction. (read pg. 158)

Mixtures with water

a combination of two or more substances in which each substance retains its individual characteristics and properties. ex: kool-aid

Chemistry

The study of matter

Proteins

a compound that is a primary building block of living things that is made of small carbon compounds called amino acids.

Triglyceride

a lipid that is a fat ( saturated: no double bonds) at room temperature but it is an oil (unsaturated: containing double bonds) if it is a liquid at room temperature.

Compounds

a pure substance formed when two or more elements combine

van der Waals forces

When molecules come together, the attractive forces between these positive and negative regions pull on the molecules and hold them together. This phenomenon is named after Dutch physicist Johannes van der Waals. What causes water to form droplets.

elements

a pure substance that cannot be broken down into other substances by physical or chemical means.

Ion

an atom that has lost or gained one or more electron and carries an electrical charge

Ionic bonds

an electrical attraction between two oppositely charged atoms or groups of atoms called ions

Isotopes

atoms of the same elements that have the same number of electrons and protons but they have a different number of neutrons

Water is the universal solvent

because of its polarity, many solutes readily dissolve in water, which makes it the universal solvent. This means that an organism, which might be as much as 70% water, can be a container for a variety of solutions.

Enzymes

biological catalysts that speed up the rate of chemical reactions in biological processes. enzymes are essential for life. enzymes are not used up by the chemical reaction. an enzymes name describes what it does. most enzymes are specific to one reaction.

Monosaccharides or simple sugars

biologically important carbohydrates that have values of C ranging from 3 to 7. Ex: glucose plays a central role as an energy source for organisms.

Polysaccharides

many monosaccharides joined together. Ex: Glycogen is an energy storage form of glucose that is found in the liver and skeletal muscle. Starch is glucose storage found in plants. Cellulose is glucose storage in the cell walls of plants.

pH solutions

measures how acidic or basic a solution is. pH measures the amount of H+ are present in a solution. pH of 7 is neutral. pH below 7 is acidic. pH above 7 is basic.

Polymers

molecules made from repeating units of identical or nearly identical compounds called monomers that are linked together by covalent bonds.

Lipids (fats)

molecules made of mostly carbon, hydrogen, and oxygen that make up fats, oils, and waxes. primary function is to store energy.

Polar molecules

molecules that have and uneven distribution of charges, meaning that they have oppositely charged regions. Ex. water molecules: water molecules are made of one oxygen atom covalently bonded to two hydrogen atoms. The electrons are drawn more to the oxygen atom giving it a slightly negative charge which make the hydrogen atoms more positive.

electrons

negatively charged particles that are located outside of the nucleus. atoms contain an equal amount of protons and electrons so an atoms electrical charge is 0.

Chemical reaction

the process by which atoms or groups of atoms in substances are reorganized into different substances. chemical bonds are broken and or formed during chemical reactions. clues that a chemical reaction has taken place: change in appearance, the production of heat or light, and formation of a gas, liquid, or solid.

Disaccharides

two monosaccharides linked together. Like glucose, disaccharides serve as an energy source. Ex: sucrose or table sugar, or lactose or milk sugar.

Homogeneous mixtures (solution)

when a mixture has a uniform composition throughout. Ex: when you make kool-aid, kool-aid is on the top, in the middle, and on the bottom.