Biology 20 - Digestion vocabulary Flashcards
(43 cards)
Macromolecules
Complex molecules that are composed of smaller subunits, known as monomers, which are linked together to form polymers. Examples include carbohydrates, proteins, lipids, and nucleic acids, which play crucial roles in biological processes.
Dehydration Synthesis
A chemical reaction in which monomers are joined together to form polymers, with the removal of a water molecule. This process is essential for building macromolecules such as carbohydrates, proteins, and nucleic acids.
Hydrolysis
The reverse of dehydration synthesis, hydrolysis is a chemical reaction that breaks down polymers into monomers by the addition of water molecules. This process is crucial for digestion, as it allows organisms to extract nutrients from macromolecules.
Carbohydrates
Organic compounds consisting of carbon, hydrogen, and oxygen atoms, usually in the ratio of 1:2:1. Carbohydrates serve as a major source of energy and include sugars, starches, and cellulose.
Proteins
Complex macromolecules composed of amino acid subunits linked together by peptide bonds. Proteins play diverse roles in the body, including structural support, enzyme catalysis, and cell signaling.
Lipids
Diverse group of molecules that are insoluble in water but soluble in organic solvents. Lipids include fats, oils, phospholipids, and steroids, and serve functions such as energy storage, cell membrane structure, and hormone production.
Peptide Bond
A covalent bond formed between the amino group of one amino acid and the carboxyl group of another amino acid during protein synthesis. Peptide bonds link amino acids together to form polypeptide chains.
Nucleic Acids
Macromolecules responsible for storing and transmitting genetic information. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are the two main types of nucleic acids, composed of nucleotide subunits containing a sugar, phosphate group, and nitrogenous base.
Vitamins
Essential organic compounds required in small amounts for various metabolic processes in the body. Vitamins act as coenzymes, facilitating enzyme activity, and are crucial for maintaining health and preventing deficiencies.
Minerals
Inorganic compounds essential for various physiological functions, such as bone formation, nerve function, and fluid balance. Minerals include calcium, iron, potassium, and zinc, and must be obtained from the diet.
Catalyst
A substance that speeds up the rate of a chemical reaction without undergoing any permanent change itself. Catalysts lower the activation energy required for a reaction to occur, thereby increasing reaction rates.
Enzyme
A biological catalyst, usually a protein, that enhances the rate of specific biochemical reactions within cells. Enzymes bind to specific substrates and facilitate their conversion into products, playing essential roles in metabolism, digestion, and other physiological processes.
Mouth
The oral cavity, where the process of digestion begins. The mouth is involved in both mechanical (chewing) and chemical (salivary amylase) digestion of food.
Amylase
An enzyme produced in the mouth and pancreas that catalyzes the hydrolysis of starch into simpler sugars, such as maltose and glucose. Amylase initiates the breakdown of carbohydrates during digestion.
Esophagus
A muscular tube connecting the throat (pharynx) to the stomach. The esophagus transports swallowed food (bolus) from the mouth to the stomach through peristaltic contractions.
Peristalsis
Wave-like muscular contractions that propel food through the digestive tract, including the esophagus, stomach, and intestines. Peristalsis ensures the efficient movement of food and facilitates digestion and absorption.
Esophageal Sphincter
A muscular ring at the junction between the esophagus and stomach, known as the lower esophageal sphincter or cardiac sphincter. This sphincter regulates the passage of food from the esophagus into the stomach and prevents gastric reflux.
Pyloric Sphincter
A muscular valve located at the junction between the stomach and the small intestine (duodenum). The pyloric sphincter controls the release of partially digested food (chyme) from the stomach into the small intestine.
Pepsin
An enzyme produced in the stomach that breaks down proteins into smaller peptides by hydrolyzing peptide bonds. Pepsin is activated by the acidic environment of the stomach and plays a crucial role in protein digestion.
Small Intestine
The longest part of the digestive tract, where most digestion and nutrient absorption occur. The small intestine consists of three segments: duodenum, jejunum, and ileum, and is lined with villi and microvilli to increase surface area for absorption.
Segmentation
A rhythmic contraction and relaxation of segments of the small intestine that mixes chyme with digestive juices and enhances nutrient absorption. Segmentation helps break down food particles and facilitates contact with the intestinal lining for absorption.
Duodenum
The first segment of the small intestine, located immediately after the stomach. The duodenum receives partially digested food (chyme) from the stomach and mixes it with bile and pancreatic enzymes for further digestion.
Villi
Tiny, finger-like projections covering the inner surface of the small intestine. Villi increase the absorptive surface area of the small intestine and contain blood vessels and lacteals for the absorption of nutrients into the bloodstream and lymphatic system.
Microvilli
Microscopic projections extending from the surface of absorptive cells (enterocytes) on the villi of the small intestine. Microvilli further increase the surface area available for nutrient absorption and contain enzymes involved in final digestion.