digestive system Flashcards
(29 cards)
Macromolecules
: larger, more complex assemblies of organic molecules needed to provide energy, to regulate cellular activities and to build and repair tissues.
Function: required to perform life functions and obtain energy for survival (maintaining metabolism = chemical processes carried out by cells to maintain life)
provide energy, to regulate cellular activities and build/repair tissues
Organic molecules → carbon bonded to hydrogen as well as to other atoms EX Oxygen, Sulfur, Nitrogen
4 ESSENTIAL: carbohydrates, lipids, proteins, nucleic acids (cannot be made by body, obtained from food)
Simple carbs
SIMPLE CARBS( Provide short-term/long-term energy storage, provide materials to build cell membranes) - monosaccharides(C6H12O6) & disaccharides(C12H22O11)
EX: MONO → glucose, fructose, galactose
EX: DI → sucrose (glucose + fructose), maltose (glucose x2), lactose (glucose + galactose)
3-7 carbon atoms
Complex carbs
COMPLEX CARBS ( Provide short-term/long-term energy storage, provide materials to build cell membranes) - polysaccharides
EX: starch ,cellulose, glycogen
Made of glucose sub-units, many linked sugars
Glycerol + fatty acids
- Insoluble in water
- Basic structure → glycerol - 3 carbon atoms attached to fatty acid chain (trail of carbon and hydrgoen)
Function: could be for energy storage // phosoplipids form the membrane that separates a cell from its external environment
EX: butter, oils
Triglycerides = most common type of fat in blood stored in cells, glycerol + 3 fatty acids, converted from calories the body doesn’t use right away, released between meals
Fatty acids
Saturated:
Single bonds between carbon atoms
Bad, may raise cholesterol levels
Unsaturated:
Have at least one double bond
Monounsaturated:
1 double bond in the fatty acid chain
Polyunsaturated:
2 or more carbon double bonds
Fatty Acid STRUCTURE: Hydrocarbon chain + Carboxyl Group (HO-C=O)
Glycogen storage
- main source of energy stored in liver and muscles
- stored glucose=glycogen
LDL vs HDL cholestrol
Low-density lipoprotein: LDL carries from liver->body
high LDL= High plaque
High density Lipoprotein
carries from boday(bloodstream)
->liver
Proteins (amino acids, r groups)
Function:help build and repair muscles and cell membranes
Made from amino acids, joined by peptide bonds
Chains of amino acids = polypeptide, two amino acids = dipeptide
Most enzymes = proteins and antibodies
20 AMINO ACIDS, 8-9 essential
STRUCTURE of Amino acid: Amino group (NH2) + Hydrogen (H) + Carboxyl Group (O-H-C=O) + “R” side chain
Dehydration synthesis vs hydrolysis
chemical reaction that involves the loss of a water molecule from the reacting molecule.
EX: glucose + fructose = sucrose → monosaccharide + monosaccharide = disaccharide
Hydrolysis: adds water back into the chemical reaction
Micronutrients
-Inorganic and organix substances that enable chemical reactions to occur
Function: enable/aid in tissue development, growth and immunity
Minerals
Calcium: forming bone
Iron: make hemoglobin
Magnesium: enzyme functions, protein production
Potassium: conduct nerve signals, control muscle
Sodium: conduct nerve signals, balance body fluid
Vitamins
A: good vision + skin bones
B: metabolize carbohydrates, muscle growth
C: help immune system
D: absorb calcium, make bone
E: strengthen RBC membrane
WATER SOLUBLE VS NON-WATER SOLUBLE → BC vs ADEK
Deficiencies
- Nitrogen deficiency causes hair loss, delayed wound healing, muscle weakness and wasting.
- Calcium deficiency increases the risk of osteoporosis, results in weak hair, nails, memory loss and seizures.
- Magnesium deficiency can cause tics, muscle spasms and cramps, seizures, anxiety and irregular heart rhythms.
- Iron deficiency (very common) symptoms include fatigue, slow cognitive and social development, difficulty maintaining body temperature, decreased immune function and glossitis
Potassium deficiency causes weakness, tiredness, cramping in muscles, tingling or numbness, nausea and vomiting.
Copper deficiency symptoms include fatigue, paleness, low body temperature, anemia, brittle bones, muscle soreness, joint pain, stunted growth, bruising, and sores.
Function of water in the body
Functions: transportation of nutrients, flushing toxins. Lubricating tissues/joints, forming body fluids (blood, mucus..), regulating body temperature, eliminating waste
Need to drink water to replace lost fluids in sweating, urine, perspiration
Alimentary canal + acessory organs
Alimentary canal → where food passes through
Accessory organs → food does not pass through
Mechnical vs chemical digestion
MOUTH → the teeth bite/grind/chew the food while saliva moistens the food and releases enzymes to help break it down (starch → maltose)
STOMACH → the stomach churns the food and mixes it with gastric juices, the HCL helps break down the food while enzymes (pepsin) help break down proteins
main enzymes
Carbohydrase
Break down carbohydrates
EX: amylase, made by salivary glands and mouth, // starch, glycogen
Lipase
Break down fats
EX: pancreatic lipase, made in pancreas works in small intestine
Protease
Break down proteins
EX: pepsin, made in stomach
EX: Trypsin, made in pancreas,work in small intestine, break down polypeptides
Nuclease
Break down nucleic acid
Peptidase
Break down peptides
In pancreas + small intestine
Enzyme – optimal levels? Factors that affect enzyme function (temperature, pH)
Pepsin - best atlow pH
Trypsin - best at mid pH (6-8) small intestine
Energy added at higher temperatures → enzyme activity increases
Chemical bonds = too weak to maintain enzyme’s shape, change in structure
4 stages of food processing
1.Ingestion – taking in or eating food
2.Digestion- mechanical or chemical
3.Absorption – from digestive to circulatory
4.Elimination – removal of waste
herbivores
consume plants
dentition and digestive tract → adapted to intake large amounts of plant material
must consume a large amount of plant material to gather enough energy and nutrients → carbohydrates in
the plant are protected by cellulose which the
digestive system has difficulty breaking down
There are enzymes and bacteria in the digestive
system that break down the cellulose → easier access to carbs
carnivors
meat eating mammals
The distinctive feature = carnassial teeth. The upper fourth molar and the lower first molar = sharp edges, slice through flesh
Predators, expend a large amount of energy hunting for their food.
Meat = low in carbohydrate but rich in other nutrients.
Meat is easier to digest than plant material → carnivores have shorter digestive systems
Omnivores
Have digestive systems and dentition that is adapted to eating both plant and animal tissues.
Teeth pattern vary but each one will have incisors to cut meat, canines to grasp and tear meat and molars to crush and grind plant matter.
Energy requirements differ for people how?
Influential factors:
Age: growing children needmore than adults
Gender: Men have more requirements than women, exception of pregnant women
Occupation: More demanding jobs may require more energy
Climate: cold climates require more energy than warm climates
ACTUAL AMOUNT → Basal Metabolic Rate (calories needed for body to function)
FOOD → energy, growth repair, insulation, health
Parts of Digestive System and functions of organs, glands, ducts, sphincters and valves
Functions of Saliva:
*chemical breakdown of starch to maltose
*moistens food
*lubricates food
Salivary Glands:
a. sublingual (smallest glands- under tongue)
b. submandibular (at lower jaw level)
c. parotid (biggest – cheek level)
* Glands in the lining of the esophagus produce mucus which keeps the passage moist and aids in swallowing
Ducts:
Carry bile between organs
Sphincters:
When the food reaches the opening of the stomach, it must pass through a sphincter called the “esophageal” or “cardiac” sphincter
The closing of this sphincter, after food passes, prevents acid reflux (food coming up from stomach into esophagus)
The pyloric sphincter controls amount of food moving into the small intestine from the stomach
