Bio 20, The digestive and respiratory systems

Everything involved with the human digestive and respiratory systems

What are carbohydrates composed of?

C, H, O

Nucleases

enzyme that breaks down DNA and RNA into nucleotides

Substrates

substances that enzymes act on

Lipids

fats that are used for energy storage, insulation, membranes (phospholipid), and hormones

Saturated fats

Fat molecules with no double bonds between the carbon atoms

Unsaturated fats

Fat molecules with double bonds between the carbons

Nucleic acid

long chains of nucleotides that direct the growth and development of all organisms

What are the two types of nucleic acid?

DNA and RNA

Proteins

made of amino acid sub units bonded together by peptide bonds

Peptide bond

bond between the amino group of one one amino acid and the carboxyl group of another in a protein

Macromolecules

Large molecules made up of smaller molecules called subunits

Large intestine

Portion of the digestive system used to concentrate and eliminate waste comprised of the colon, rectum, and anal canal

Elimination

The removal of a waste product from the body

Absorption

transporting nutrients from the digestive tract to the blood stream

Mouth

First structure in the GI tract that chews and mixes food with saliva (physical and chemical)

Pharynx

Common passage-way of food and air

Epiglottis

Flap over the trachea near the esophagus that prevents food from entering the lungs

Esophagus

directs food from the mouth to the stomach using peristalsis and gravity

Peristalsis

wave like muscle contractions in the esophagus

Stomach

adds acid, enzymes, and fluid to the food while churning, mixing and grinding the food into a liquid mass

Chyme

liquid food mixed with gastric juices from the stomach

What does the stomach use to digest?

It uses enzymes for chemical digestion and muscle contractions for physical digestion

Esophageal sphincter

small muscle between the esophagus and stomach that controls the flow of food

Pyloric sphincter

Small muscle between the stomach and the duodenum (small intestine) that controls the flow of food

What is gastric juice made of?

Water, mucus, salt, HCl, and enzymes

Small intestine

A long tube that secretes macromolecule digesting enzymes and absorbs hydrolyzed molecules into the bloodstream

Three regions of the small intestine

duodenum, jejunum, and ileum

Segmentation

contractions of circular muscle of the small intestine

Liver

creates bile which digests fats

Bile

digestive fluid emulsifies fat (physical digestion)

Gall bladder

Stores extra bile from the liver in-between meals and sends bile into the duodenum

Pancreas

Secretes bicarbonate to neutralize stomach acid and digest macromolecules at the duodenum

What is pancreatic fluid made of?

Enzymes like trypsin, chymotrypsin, pancreatic amylase, and lipase

Salivary amylase

Enzyme in saliva that breaks down starch into simpler sugars

Gastrin

stomach hormone that stimulates the secretion of hydrochloric acid and the inactive precursor molecule of pepsin from glands in the stomach

Carbohydrases

an enzyme that catalyses the hydrolysis of carbohydrates

Catalyst

a trigger that speeds up a reaction

triglycerides

comprised of three fatty acids and one glycerol

Lipase

Enzyme that catalyzes the hydrolysis of triglycerides into glycerol and fatty acids

Proteases

Enzyme that hydrolyzes the peptide bonds that link amino acids in proteins and peptides

Trypsin/chymotrypsin

a digestive enzyme that breaks down proteins in the small intestine

Digestive system

system used to break down food into its chemical components using enzymes and absorb the nutrients

GI tract

structures in the digestive system that food moves through Ex. stomach

Rugae

folds along the sides of the stomachs used to increase the surface area and for expansion as the stomach fills

Villi

Small finger like folds along the inside of the small intestine used to absorb nutrients more efficiently

Bolus

mass of chewed food mixed with saliva on its way down to the stomach

Competitive inhibitor

When a different chemical attaches to an enzymes active site and blocks any substrate from binding

non-competitive inhibitor

when other chemicals attach to the active site of an enzyme, causing the enzyme to morph and change shape and prevent the substrate from bonding

Carbohydrates

Used as fuel, are a major energy source, and an important structural material

What are carbohydrates commonly classified as?

Sugars, Starches, Cellulose

What are carbohydrates properly classified as?

Monosaccharides, Disaccharides, Polysaccharides

Examples of monosaccharides?

Glucose, Fructose, Galactose, Ribose

What is dehydration synthesis?

formation of a new covalent bond by releasing a OH group and a H atom

What is hydrolysis?

breaking apart a macromolecule by adding a water molecule

What are examples of disaccharides?

Sucrose, Maltose, Lactos

What happens during a hydrolosis reaction

Disaccharides are broken apart

What are polysaccharides?

Long chains of multiple sugar units

What are disaccharides?

two bonded monosaccharides

What is a monosaccharide

one sugar compound

What are the three main polysaccharides?

Starch, Glycogen, Cellulose

What does starch turn into when digested?

Sugars

What enzyme breaks down starch?

Amylases

Where is glycogen stored?

In the liver and muscles

Where is cellulose found?

Plants

What is cellulose used for in humans?

Fibre and bulk

What are lipids composed of?

Glycerol, 3 Molecules of Fatty Acids

What do lipids exist as?

Oils and Fats

What are proteins made up of?

Long chains of amino acid

A temporary or reversible change in the shape of a protein is called:

Denature

A permanent change in the shape of a protein is called;

Coagulation

What are enzymes?

Protein molecules that act as biological catalysts

What are co-enzymes?

Usually Vitamins

What are cofactors?

Small inorganic ions

5 Factors effecting enzyme activity

Temperature, pH, Concentration of Enzyme/Substrate, Competitive Inhibitors, Negative Feedback

What temperature do enzymes work the best in in humans

30C

Homeostasis

Maintenance of a stable or constant internal environment

Metabolism

The sum of all chemical reactions occurring within an organism

Buffers

Act to ensure/maintain a constant pH

What are the 2 main functions of the digestive system?

Break down food and absorb nutrients

Mechanical Digestion

Increases surface area in the mouth by teeth chewing and stomach churning.

Chemical Digestion

Uses enzymes, occurring in the mouth, stomach, and small intestine

What does saliva contain

Mucin, Amylose

What does Mucin do?

Binds food together for swallowing

What does Amylose do?

Chemically digests starch to maltose to form bolus

What do the glandular cells in the esophagus do?

Secrete mucin to lubricate the food passage

What is the cardiac sphincter?

A ring of muscles at the bottom of the esophagus that allows food to enter stomach

What does Gastric Juice contain?

Pepsinogin, rennin, HCl

What is Pepsinogin?

An inactive protein digesting enzyme

what does pepsinogen turn into when HCl is added

Pepsin

Pepsin

protein-digesting enzyme secreted in the stomach that activates with HCl

Chyme

Liquidy food from the stomach

What controls food from leaving the stomach?

Pyloric Sphincter

What is the Duodenum?

The first part of the small intestine

Nasal cavity

space in your face behind your nose that acts as a passage way for air

Nasal passage

Warms, moistens, and cleans incoming air

Larynx

voice box made of cartilage that contains the vocal cords

Glottis

opening to trachea

Trachea

Cartilage supported tube that transports air into the lungs

Cilia

small hairs that line the inside of the nose and nasal cavity that help clean and filter incoming air

Upper respiratory tract

the top half of the respiratory system from the trachea and higher