Biology Test 3

Activation energy

The activation energy is the energy required to start a reaction. Enzymes are proteins that bind to a molecule, or substrate, to modify it and lower the energy required to make it react.

active site

The active site refers to the specific region of an enzyme where a substrate binds and catalysis takes place or where chemical reaction occurs. It is a structural element of protein that determines whether the protein is functional when undergoing a reaction from an enzyme.

Hydrogen bonds

The bond formed by a hydrogen on one molecule's attraction to the negatively charged oxygens or nitrogens on another molecule. EXAMPLE: nucleotides in double-stranded DNA

Adhesion

The force of attraction between unlike molecules, or the attraction between the surfaces of contacting bodies.

induced-fit model

The induced fit hypothesis proposes that the binding of the substrate by the enzyme changes the structure of the enzyme, resulting in an even greater affinity of the enzyme for the substrate. The site on an enzyme that binds the substrate (known simply as the substrate binding site) is most often a pocket or cleft in the approximately globular structure of the enzyme.

Triglycerides

The major form of fat stored by the body. A triglyceride consists of three molecules of fatty acid combined with a molecule of the alcohol glycerol. Triglycerides serve as the backbone of many types of lipids (fats). Triglycerides (fats) contain a glycerol and 3 fatty acids and is stored mainly in the body's adipose tissue

Specific heat

The measure of the heat energy required to increase the temperature of a unit quantity of a substance by unit degree.

allosteric site

The place on an enzyme where a molecule that is not a substrate may bind, thus changing the shape of the enzyme and influencing its ability to be active.

anabolism

The process involving a sequence of chemical reactions that constructs or synthesizes molecules from smaller units, usually requiring input of energy (ATP) in the process. A constructive type of metabolism.

tertiary structure

The tertiary structure will have a single polypeptide chain "backbone" with one or more protein secondary structures, the protein domains. Amino acid side chains may interact and bond in a number of ways. The interactions and bonds of side chains within a particular protein determine its tertiary structure. Tertiary structures which form globular proteins are still determined by the original amino acid sequence. They form from interactions between the different "R" groups causing them to fold to create an active protein

Ester bond

These esters can be formed when a carboxylic acid (consisting of a carbon, an oxygen, an OH group, and a hydrocarbon) reacts with an alcohol group; this process also forms a water molecule. Triglyceride lipids are composed of three ester linkages and are an extremely important biological molecule.

Fibrous proteins

They are long filamentous proteins only found in animals. Water insoluble and inert structural or storage proteins. FUNCTION: construct connective tissue, tendons, bones, and muscle fiber.

Trans-fatty acid

Trans fatty acids lower HDL (good) cholesterol. They have hydrogens on the opposite side of the double bond.

polymer

A chemical compound that is made of small molecules that are arranged in a simple repeating structure to form a larger molecule

condensation reaction

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

End-product inhibition

A common way of regulating enzyme activity in which the reaction product (or in the case of a biosynthetic pathway, the product of the reaction sequence) inhibits the enzyme activity.

disaccharide

A disaccharide is a carbohydrate that is formed when two monosaccharides are joined together and a molecule of water is removed from the structure. Examples: Lactose is a disaccharide formed from the combination of galactose and glucose.

Unsaturated fatty acid

A form of fatty acid containing one or more double (or triple) bonds and therefore can absorb additional hydrogen atoms.

Glycosidic Bond

A glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate.

monomer

A monomer is a molecule that forms the basic unit for polymers. Monomers may bind to other monomers to form a repeating chain molecule. Ex: Glucose

peptide bond

A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule.This is a dehydration synthesis reaction (also known as a condensation reaction), and usually occurs between amino acids. A peptide bond is the type of covalent bond formed between the carboxyl group of one amino acid with the amino group of another amino acid. It is usually represented in a molecule as --N--C--.

polypeptide

A polymer of amino acids joined together by peptide bonds.

denature

A process in which the folding structure of a protein is altered due to exposure to certain chemical or physical factors (e.g. heat, acid, solvents, etc.), causing the protein to become biologically inactive.

Enzyme

A protein molecule that helps other organic molecules enter into chemical reactions with one another but is itself unaffected by these reactions. In other words, enzymes act as catalysts for organic biochemical reactions.

proteome

A proteome is all of the different kinds of proteins produced by a genome, cell, tissue or organism at a certain time. Proteomes vary in different cells (different cells make different proteins) and at different times within the same cell (cell activity varies) Proteomes vary between different individuals because of not only cell activity but slight variations in amino acid sequences Within species there are strong similarities between proteomes

quaternary structure

A quaternary structure of a protein refers to the assembly of multiple folded protein molecules in a multi-subunit complex. Multiple protein chains linked together.

secondary structure

A secondary structure of a protein pertains to the folding of a polypeptide chain, resulting in an alpha helix, beta sheet or a random coil structure. Structure is dependent on hydrogen bonding. Secondary structures for fibrous proteins such as collagen and keratin are determined by repeating sequences in the amino acid sequence. They are formed by the interactions between the amine and carboxyl groups

monosaccharide

A simple sugar, example: fructose, glucose, and ribose. The simplest form of carbohydrate; therefore, it cannot be broken down to simpler sugars by hydrolysis. A sugar that constitutes the building blocks of a more complex form of sugars such as oligosaccharides and polysaccharides.

Amylopectin

A soluble polysaccharide and highly branched polymer of glucose found in plants. It is one of the two components of starch, the other being amylose.

Glycogen

A substance deposited in bodily tissues as a store of carbohydrates. It is a polysaccharide that forms glucose on hydrolysis.

Catalyst

A substance that initiates or speeds up a reaction, and is unchanged at the end of it. Biological catalysts are named enzyme. Catalyst in biology is enzyme. They work by offering the molecule an alternate pathway which lowers its activation energy (when it binds to the enzyme's active site) and so results in more successful collisions and more enzyme-substrate complexes will be formed, hence more product produced and so a faster rate of reaction.

substrate

A substrate is the substance upon which an enzyme acts in an enzymatic reaction. Enzymes are biological catalysts that increase the rate of chemical reactions by decreasing the activation energy required for that reaction. An enzyme catalyzes a chemical reaction converting a substrate reactant to a product. The three-dimensional structure of an enzyme determines its substrate binding specificity.

allosteric inhibition

Allosteric inhibition is the process by which a regulatory molecule binds to an enzyme in a spot different from the active site for another molecule. This causes a conformational change in the active site for the second molecule, preventing binding. This process is also known as noncompetitive inhibition.

amino acids

Amino acids are the building blocks of proteins. There are 20 different amino acids in nature.

Amylose

Amylose is a linear polymer chain that contains hundreds to thousands of glucose molecules. One subunit of amylose is called a glucose molecule, as shown in the illustration. Each glucose or sugar molecule links to another by way of a glycosidic bond, which is a type of covalent bond.

essential amino acids

An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized de novo (from scratch) by the organism, and thus must be supplied in its diet.

protein

Any of a class of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair, collagen, etc., and as enzymes and antibodies.

carbohydrate

Any of a large group of organic compounds occurring in foods and living tissues and including sugars, starch, and cellulose. They contain hydrogen and oxygen in the same ratio as water (2:1) and typically can be broken down to release energy in the animal body.

Globular proteins

Are shaped like spheres as a result of protein folding because they're made of polypeptide chains. Soluble in water because of HYDROPHILIC side chains of amino acids on outsides of molecules and play an important role in metabolic reactions. FUNCTION: enzymes, messengers, transporters, stocks of amino acids

catabolism

Biochemical reactions that break down molecules in metabolism. Molecules may be broken down to gain their energy or to prepare them for disposal from the body.

BMI

Body Mass Index. FORMULA: kg/cm

functions of each type of biomolecule

Carbs: Starches and sugars that provide energy. Lipids: Help the body store the energy it needs in the form of fats and oils. Proteins: Carry out specific functions inside cells, and they act as enzymes to catalyze reactions all over the body. Amylase, lactase and pepsin are all proteins used in digestion, for example. Proteins are typically large molecules that can be built up from chains of amino acids called polypeptides. Nucleic Acids: Central to the function of living cells. Arranged in a linear sequence within DNA, they code for the structure and function of the body's proteins. Nucleic acids also form RNA, which acts to transmit DNA-based instructions to the cellular machinery.

Cellulose

Cellulose is a tough, water insoluble and fibrous polysaccharide. Cellulose is made up of thousands of glucose molecules attached together to form a chain.

Chitin

Chitin are polysaccharides , meaning they are composed of many linked sugar molecules. Chitin are linear, unbranched polymers of their respective sugars. Chitin is a long-chain polymer of an N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world.

Cohesion

Cohesion refers to the attraction of molecules for other molecules of the same kind, and water molecules have strong cohesive forces thanks to their ability to form hydrogen bonds with one another.

competitive inhibition

Competitive inhibition is a form of enzyme inhibition where binding of the inhibitor to the active site on the enzyme prevents binding of the substrate and vice versa.

condensation/dehydration reaction

Condensation is a chemical process by which 2 molecules are joined together to make a larger, more complex, molecule, with the loss of water.

functions of proteins

Enzymes - catalyze biochemical reactions by lowering the activation energy needed for the reaction to take place Hormones - chemical messengers that help coordinate certain regulatory activities Structural Proteins - fibrous proteins provide support and structure within the body Transport Proteins - move molecules from one place to another around the body Muscle contractions Blood clotting Defensive- Antibodies for defense against pathogens Signal Proteins, Receptor, Storage, Membrane Transport, Packing of DNA

hydrolysis

Hydrolysis, the opposite of condensation, is a chemical reaction in which water breaks down another compound and changes its makeup. Most instances of organic hydrolysis combine water with neutral molecules.

Cis-fatty acid

If the hydrogen atoms are on the same side of the double bond then the isomer is "cis". "Cis" fatty acids have a kink at the double bonds, causing the fatty acids to pack more loosely, lowering the melting point and making them liquid at room temperature

Isomer

Isomers are molecules with the same chemical formula and often with the same kinds of chemical bonds between atoms, but in which the atoms are arranged differently. Many isomers share similar if not identical properties in most chemical contexts.

Latent heat of vaporization

Latent heat is the heat released or absorbed during a phase change, where the temperature does not change. If we are talking specifically about the heat of vaporization, it is the heat that must be absorbed to change liquid water to water vapor or the heat that must be released to condense water vapor to liquid water.

lipid

Lipids include fatty acids, oils, waxes, sterols, and triglycerides. They are a source of stored energy and are a component of cell membranes.

metabolism

Metabolism consists of anabolism (the buildup of substances) and catabolism (the breakdown of substances). The term metabolism is commonly used to refer specifically to the breakdown of food and its transformation into energy.

Monosaturated fatty acid

Mono: fatty acids that have one double bond in the fatty acid chain with all of the remainder carbon atoms being single-bonded.

non-competitive inhibition

Non-competitive inhibition is a type of enzyme inhibition where the inhibitor reduces the activity of the enzyme and binds equally well to the enzyme whether or not it has already bound the substrate. Enzyme inhibition in which the inhibiting compound does not compete with the natural substrate for the active site on the enzyme but inhibits reaction by combining with the enzyme-substrate complex after the complex is formed. Binds somewhere other than the active site.

nucleic acid

Nucleic acids are biopolymers, or large biomolecules, essential for all known forms of life. Nucleic acids, which include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid), are made from monomers known as nucleotides.

nucleotide

Nucleic acids are composed of smaller units called nucleotides, which are linked together to form a larger molecule (nucleic acid). Each nucleotide contains a base, a sugar, and a phosphate group. The sugar is deoxyribose (DNA) or ribose (RNA). The bases of DNA are adenine, guanine, cytosine, and thymine.

Polyunsaturated fatty acid

Poly: Polyunsaturated fatty acids (PUFAs) are fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property.

polysaccharide

Polysaccharides are polymeric carbohydrate molecules composed of long chains of monosaccharide units bound together by glycosidic linkages and on hydrolysis give the constituent monosaccharides or oligosaccharides. They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch and glycogen, and structural polysaccharides such as cellulose and chitin.

primary structure

Primary structure of a protein is the linear sequence of amino acids. Together, this linear sequence is referred to as a polypeptide chain. The amino acids in the primary structure are held together by covalent bonds, which are made during the process of protein synthesis

Saturated fatty acid

Saturated fatty acids raise HDL cholesterol, the so-called good cholesterol. A fat with a chemical nature in which the carbon atoms are saturated with hydrogen atoms and do not contain double bonds between carbon atoms. Saturated fat is typically solid at room temperature.

Factors affecting enzyme activity

Several factors affect the rate at which enzymatic reactions proceed - temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators.

Starch

Starch is a polymeric carbohydrate consisting of a large number of glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants as an energy store.

Factors affecting enzymes

Temperature, pH, enzyme concentration, substrate concentration, and the presence of any inhibitors or activators.