Digestive Flashcards
Inorganic compounds
lack carbon-hydrogen bonds
ex. water, salts, many acid bases
Organic compounds
contain carbon-hydrogen bonds
ex. carbohydrates, lipids, proteins, nucleic acids
Carbohydrates
include sugar & starches
foods: fruits, potatoes, sugar, etc.
short term energy
monosaccharides- simple sugar
disaccharides - two simple sugars combine through dehydration synthesis
polysaccharides
Monosaccharides
simple sugar
ex. in body: glucose, fructose, galactose, ribose, deoxyribose
Disaccharides
two simple sugars combine through dehydration synthesis
ex. in normal body: sucrose, lactose, maltose
Polysaccharides
long chains linked of simple sugar
tend to be less sweet because of their chains that are harder to break down by the body
ex. for energy storage: starch, glycogen
carbohydrates provide ready and easy to use energy for cellular processes
small amounts of carbohydrates are also used for structure, cellular communication, and genetic storage (ribose(RNA) & deoxyribose(DNA))
Lipids
Fatty or oily substances
foods- egg yolks, milk products, and oils
made of carbon, hydrogen, oxygen
long-term energy
hydrophobic
Lipids-triglycerides
composed of 3 fatty acids and glycerol
saturated have straight carbon chains and are solid at room temperature like butter
unsaturated have double bonds that cause the carbon chains to bend and are liquid at room temperature like olive oil
Lipids- Phospholipids
have two fatty acid chains and a phosphate head
are polar molecules that make up cell membranes
Steroids are lipids and fat-soluble
Cholesterol- is the most important steroid in humans. Cholesterol can be ingested by consuming animal products such as meat and is essential for human life
Proteins
contain carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur
food- meat, beans, legumes
made up of amino acids joined together in chains and then folded to form a unique protein
Proteins make up enzymes, hormones, hemoglobin, transport proteins and antibodies
Enzymes- essential to every biochemical process in the body, they increase the rate of chemical reactions; if their absence/destruction the biochemical reaction will not occur
Nucleic Acids
make up the genes which provide the basic blueprint of life
composed of carbon, hydrogen, oxygen, nitrogen, phosphorous
made up of long chains of nucleic acid molecules
two kinds of nucleic acid DNA & RNA
Deoxyribonucleic acid (DNA) -nucleic acid
forms a double stranded molecule and is found in the same nucleus
Ribonucleic acid (RNA) -nucleic acid
forms a single stranded molecule and can be found in the nucleus and cytoplasm
Alimentary Canal
it is a continuous, coiled, hollow, muscular tube that winds from the mouth to the anus
It performs digestive functions
Any organ that food passes through
ex: mouth, esophagus, stomach, intestines, rectum, anus
Accessory Organs
organs that produce things needed for digestion
food does not pass through them
ex: teeth, tongue, salivary glands, liver, gallbladder, pancreas
Mouth
also called buccal cavity
Lips (mouth)
protect the opening
Teeth (mouth)
mechanical digestion
Mastication= chewing
Cheeks (mouth)
lateral walls
Hard and Soft Palates (mouth)
roof of mouth
Uvula (mouth)
keeps food out of nasal cavity
Tongue (mouth)
rolls food into a bolus and pushes it to back of mouth
Salivary (mouth)
glands produce salivary amylase (enzyme) to break down carbohydrates
Pharynx
back of throat
propels food into the esophagus
Esophagus
10 inch long muscular tube that pushes food to the stomsach
muscular contractions are called peristalsis
it connects to the stomach via the esophageal sphincter
Stomach
C shaped organ
Can hold about 4 Liters of food
Surrounded by the lesser and greater omentums
Greater omentum is riddled with fat and hangs from the stomach over the intestines-protects them
When food enters the stomach, G cells trigger the release of gastrin (hormone) in the blood
-Gastrin stimulates the GI tract to move food
-Helps pancreas produce enzymes
-Helps liver produce bile
-Helps stomach produce acid
The mixture of food and digestive juices in the stomach is called chyme
Food enters stomach thru the esophageal sphincter
Stomach churns and pummels food (mechanical digestion)
The mucosa lining of the stomach produces mucus to protect it from citric acid
The stomach is dotted with gastric glands
-Release gastric juice
Chief cells produce pepsinogen (an enzyme precursor)
Chief cells produce hydrochloric acid
-HCL coverts pepsinogen to pepsin (activates it)
-Pepsin chemically breaks down proteins
Chyme exits stomach and goes to small intestine through the pyloric sphincter
Small intestine
The small intestine is where a lot of nutrients are absorbed into the blood stream
There are many villi inside that increase the surface area for absorbing
-each villus has a capillary that helps nutrients be absorbed more quickly
The small intestine is three sections: duodenum, jejunum, ileum
The duodenum is short but this is where the majority of digestion occurs
-Brunner’s glands secrete alkaline (basic) mucus that neutralizes the acidic chyme
