Enzymes & Digestive System

Bio Unit 2

Chemical reaction

A process that involves the the breaking and forming of chemical bonds, resulting in the production of one or more new substances

Reactants

The elements or compounds that enter into a chemical reaction

Products

The elements or compounds produced by a chemical reaction

Activation energy

The energy needed to start a chemical reaction/overcome the energy barrier for the reactants

Catalyst

Substances that make a chemical reaction take place more rapidly and at lower temperatures

Enzyme

Organic molecules (proteins) that act as catalysts in biochemical reactions

Substrate

The specific molecule upon which an enzme acts to catalyze a biochemical reaction

Active site

The pocket or indentation where substrates fit with enzymes

Enzyme-substrate complex

The binding of an enzyme and a subtrate molecule

Induced fit

When an enzyme changes fit slightly to better accomodate the substrate

Specific enzyme inhibitor

A molecule that targets and blocks the activity of a specific enzyme

Competitve inhibitor

Specific enzyme inhibitor » directly blocks the enzyme from binding with the substrate

Noncompetitive inhibitor

Specific enzyme inhibitor » allows the enzyme to bind with the substrate, but blocks the reaction from taking place

Non-specific enzyme inhibitor

A molecule that inactivates multiple types of enzymes

Denature

When an enzyme loses its particular shape and no longer has a complimentary fit to its substrate or paricipate in the chemical reaction

Ingestion

The process of taking food into the body

Digestion

The process of breaking down food chemically into their building blocks

Absorption

The process of taking in valuable nutrients into the bloodstream

Elimination

The process of releasing solid waste from the body

Mechanical digestion

Physically breaking down food

Chemical digestion

Chemical breakdown of food into simpler nutrients that can be absorbed

Mouth

The opening to the digestive tract

Teeth

Helps with mechanical digestion in the mouth

Saliva

Produces enzymes that start chemically digesting food

Esophagus

A long tube that food enters after swallowing. It pshes food down using peristalsis

Peristalsis

Performed in digestion by smooth muscle found in the digestve tract. Helps move food down the esophagus through wave-like movements

Epiglottis

Flap of tissue that directs air into the trachea when breathing and food into the esophagus when swallowing

Sphincter

It opens and closes to conrol the flow of food and liquid between stomach and esophagus

Stomach

A hollow muscular sac that stores and digests food. It performs mechanical digestion through the churning in its walls, while chemical digestion comes in the form of gastric juices (HCl acid) and enzymes (pepsin)

Chyme

Digested food in the stomach

Villus

Finger-like folds in the small intestine’s inner lining that absorb nutrients and increase surfae area

Pancreas

Accessory organ that breaks down carbs, fats, proteins, and produces insulin. Produces the proteolytic enzyme trypsin (breaks down protein) and enzymes that neutralize the acid chyme.

Liver

Produces bile, which breaks down fat, and catalase, an enzyme that breaks down the toxic byproduct hydrogen peroxide into water and O2

Gallbladder

Stores bile from the liver

Small intestine

Primary role is to absorb nutrients. Uses enzymes produced on its own as well as enzymes from the pancreas and bile.

Large intestine

Reabsorbs water and transports undigested food

Salivary amylase

Enzyme produced by salivary glands in the mouth that breaks down starch (carbohydrates)

Proteases

Enyzmes that break down proteins. Two examples are pepsin (produced in the stomach) and trypsin (produced in the pancreas)

Lipase

Enzymes that break down lipids

Accessory organs

Structures that help with digestion but are not part of the digestive tract. Includes the liver, gallbladder, pancreas

Digestive organs

Structures that form part of the digestive tract where digestion takes place. Part of the alimentary canal (whole passage along which food passes through the body from the mouth to the anus)

Primary structure

A simple amino acid sequence fromed by dehydration synthesis and connected with peptide bonds between carboxyl and amino groups

Secondary structure

Protein begins to fold with hydrogen bonds between carboxyl and amino groups. Two possible shapes: alpha helices and beta pleated sheets

Tertiary structure

Protein finishes folding and becomes generally functional. R-group activates and has different interactions: disulfide bridge, hydrophobic interactions, hydogen bonds, ionic bonds

Disulfide bridge

Link between two sulfur atoms

Hydrophobic interactions

Hydrophobic parts of the protein (i.e., nonpolar) fold inwards

Ionic bonds

Bonds between a positively charged amino acid and a negatively charged amino acid

Quaternary structure

Multiple proteins come together to form a protein complex