Enzymes & Digestive System Test

Mechanical digestion

is the physical breakdown of food into smaller pieces, accomplished by teeth and churning of digestive tract

Chemical digestion

is the enzymatic breakdown of food into simpler molecules, primarily occurring in the stomach and small intestine.

appendix

is a small structure attached to the large intestine- vestigial structure

Appendicitis

is the inflammation of the appendix

peritonitis

is the inflammation of the abdominal cavity lining, often due to infection or irritation.

Ingestion

taking in whole, undigested food

egestion

excretion of materials not absorbed by the body

goblet cells

cells that produce mucus that protects stomach from its own acidity

Mucus

produced by stomach, thick substance that protects stomach

Anus

opening that gets rid of waste

absorption

uptake of the products of digestion

bile

produced by liver and stored in gall bladder. bile emulsifies fat (breaks into smaller droplets) so there’s more surface area for enzyme action

common bile duct

how bile enters the duodenum (small intestine)

bolus

chewed food mixed with saliva

cardiac sphincter

controls entrance of food into the stomach

cecum

area below the junction with small intestine into large intestine

chyme

when bolus becomes thick and soupy

colon (3 parts)

ascending, transverse and descending colon

digestion

mechanical and chemical breakdown of food

duodenum

the first portion of the small intestine (25cm)

bacteria

produce vitamins in the large intestine from break down of indigestible materials

emulsifier

breaks things down into smaller pieces

tongue

aids in mechanical digestion by mixing the food that was chewed by teeth

esophagus

digestive tract that carries food to stomach

hard palate

anterior roof section of the mouth, composed of bones (mechanical digestion as tongue mashes food against it)

soft palate

posterior roof section of mouth, composed of muscles (swallowing)

teeth

physical breakdown of food into smaller forms

gall bladder

stores and releases bile through common bile duct

gastric gland

makes and releases gastric juice in stomach

heartburn

when acidic contents from stomach go back up into esophagus through cardiac sphincter valve

hydrochloric acid

located in stomach (gastric juice) makes it acidic, activates pepsin

lacteal

where fatty acids and glycerol are absorbed to get into the lymphatic system

large intestine

aka “colon” moves indigestible materials from small intestine to the rectum, responsible for absorbing water, salts, and vitamins

liver

stores glucose as glycogen and then breaks back into glucose when needed (homeostasis) and produces bile to emulsify fat

microvilli

located on villi, maximizes the surface area of small intestine

villi/villus

in small intestine, finger-like projections that increase surface area

mouth

mechanical and chemical digestion occur , contains 3 pairs of salivary glands containing salivary amylase. neutral pH

pancreas

produces insulin and glucagon-hormones that keep glucose level normal. insulin is realeased for high blood glucose and glucagon is released for low blood glucose. produces pancreatic juice

pancreatic juice

sodium bicarbonate, trypsin, pancreatic amylase, lipase, nuclease

pepsinogen

pepsin that hasn’t been activated by HCl

peristalsis

coordinated muscular contractions made by esophagus

pyloric sphincter

one way door out of stomach into small intestine

pharynx

where food and air pass through

rectum

last 20cm of large intestine where it opens at the anus

saliva

secreted by salivary glands, mix with food to create bolus

salivary glands

secrete saliva, 3 pairs located in mouth

small intestine

mostly chemical digestion and absorption occur here, basic pH of 8.5, 3m long. contains pancreatic juice and uses sodium bicarbonate to neutralize the acidic chyme from stomach, produces maltase and peptidase

sodium bicarbonate

neutralizes acidic chyme from stomach in small intestine

stomach

mechanical and chemical digestion occur here, pH of 2. contains goblet cells and mucus. gastric juice here

ulcer

occurs when HCl penetrates through mucus and dissolves there stomach lining

glucose & amino acids

absorbed by villi in small intestine

glycerol and fatty acids

absorbed into the lacteals of lymphatic system

defecation

elimination of solid waste

glycogen

how liver stores glucose

insulin

released by pancreas to bring down blood glucose levels

glucagon

released by pancreas to increase blood glucose levels

jaundice

occurs when you get a gall stone in gall bladder and they block common bile duct

gall stones

cholesterol content of bile can build up to form gall stones in gall bladder

exocrine

pancreases exocrine function is secreting pancreatic juice into pancreatic duct

endocrine

pancreases endocrine function is secreting its hormones (insulin & glucagon) into blood

lleocecal valve

a sphincter muscle situated at the junction of ileum

enzyme-substrate complex

when the substrate attaches to the enzyme

catalyst

speeds up reactions and lowers activation energy

active site

where substrate binds to enzyme

allosteric site

site at the other end of active site

cofactor

inorganic ions that are composed of Cu, Zn, and Fe- help with keeping shape/structure of enzymes

inhibitor

a separate molecule that can either compete with substrate or bind to different end of enzyme

non-competitive inhibition

molecule binds with enzyme at the allosteric site, changes shape of active site so substrate can no longer attach- NO reaction

competitive inhibition

molecule similar is she competes with substrate to reach active site first, when inhibitor gets there first NO reaction occurs

thyroxin

a hormone secreted by thyroid gland, it controls the metabolism of all cells in body

hypothyroidism

decreased product of thyroxin leading to slower metabolism- weight gain, fatigue, slowed heart rate, enlarged thyroid gland

hyperthyroidism

increased production of thyroxin leading to faster metabolism-severe weight loss, rapid heart rate

substrate

the “reactants” of the metabolic pathway, binds to enzymes at active site to create products

vitamin

components of coenzymes, molecules required in our diet

activation energy

amount of energy needed to complete a reaction

coenzyme

organic non-protein molecules composed of vitamins, vitamin deficiency will lead to decrease in coenzymes therefore lack of enzyme activity

denaturation

when a molecule is broken down and killed

induced fit model

when active site undergoes a slight change in shape to “best fit” the substrate

metabolism

the sum of all reactions that occur in a cell

enzyme specificty

enzymes are very specific and only complex with their specific “ase” ending

factors effecting enzymes

1. substrate concentration- more active sites filled reaction increases. 2. temp/pH- optimal temp for enzymes is 40 degrees, once enzyme isn’t in functional temp or pH it will denature 3. enzyme concentration- more enzymes faster reaction rate 4. inhibitors- competitive and non-competitive 5. enzyme helpers- cofactors and coenzymes that assist enzymes with their functions