digestive system

Question 1

Macromolecules

Answer 1

: 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)

Question 2

Simple carbs

Answer 2

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

Question 3

Complex carbs

Answer 3

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

Question 4

Glycerol + fatty acids

Answer 4

• 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

Question 5

Fatty acids

Answer 5

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)

Question 6

Glycogen storage

Answer 6

• main source of energy stored in liver and muscles
• stored glucose=glycogen

Question 7

LDL vs HDL cholestrol

Answer 7

Low-density lipoprotein: LDL carries from liver->body
high LDL= High plaque
High density Lipoprotein
carries from boday(bloodstream)
->liver

Question 8

Proteins (amino acids, r groups)

Answer 8

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

Question 9

Dehydration synthesis vs hydrolysis

Answer 9

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

Question 10

Micronutrients

Answer 10

-Inorganic and organix substances that enable chemical reactions to occur
Function: enable/aid in tissue development, growth and immunity

Question 11

Minerals

Answer 11

Calcium: forming bone
Iron: make hemoglobin
Magnesium: enzyme functions, protein production
Potassium: conduct nerve signals, control muscle
Sodium: conduct nerve signals, balance body fluid

Question 12

Vitamins

Answer 12

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

Question 13

Deficiencies

Answer 13

• 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.

Question 14

Function of water in the body

Answer 14

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

Question 15

Alimentary canal + acessory organs

Answer 15

Alimentary canal → where food passes through
Accessory organs → food does not pass through

Question 16

Mechnical vs chemical digestion

Answer 16

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

Question 17

main enzymes

Answer 17

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

Question 18

Enzyme – optimal levels? Factors that affect enzyme function (temperature, pH)

Answer 18

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

Question 19

4 stages of food processing

Answer 19

1.Ingestion – taking in or eating food
2.Digestion- mechanical or chemical
3.Absorption – from digestive to circulatory
4.Elimination – removal of waste

Question 20

herbivores

Answer 20

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

Question 21

carnivors

Answer 21

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

Question 22

Omnivores

Answer 22

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.

Question 23

Energy requirements differ for people how?

Answer 23

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

Question 24

Parts of Digestive System and functions of organs, glands, ducts, sphincters and valves

Answer 24

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

Question 25

Pathway of food

Answer 25

Mouth: Chews food and mixes it with saliva
Salivary glands: Produces saliva which contains a starch digesting enzyme called salivary amylase
Pharynx: Swallows the chewed food mixed with saliva called bolus
Esophagus: Moves the bolus to the stomach
Stomach: Mixes and churns food with gastric juices that contain acid and protein-digesting enzyme called pepsin creating chyme.
Liver: Makes bile which aids in digestion and absorption of fat
Pancreas: Releases bicarbonate to neutralize intestinal contents; produces enzymes that digest carbohydrates, proteins and fats
Gallbladder: Stores bile and releases it into small intestine when needed
Small intestine (Duodenum - Jejunum - Ileum) : Digests food and absorbs nutrients into blood and lymph
Large intestine (Cecum - Ascending Colon - Transverse Colon - Descending Colon - Sigmoid Colon) : Absorbs water and some vitamins and minerals home to intestinal bacteria; passes waste material
Rectum: Where the waste is stored before it leaves the body
Anus: Opens to allow waste to leave the body

Question 26

Physical characteristics of organs

Answer 26

Mesentery: membrane keeps organs in place
Rugae: folds in stomach
Villi: finger-like projections help absoprtion

Question 27

Peristalsis

Answer 27

Wave-like muscular contractions (esophagus)

Question 28

Accessory organs

Answer 28

Liver-bile empties into Gallbladder/.duodemun
Gallbladder- stores bile empties duodenum
pancreas- produces insulin aids with enzymes absorption (dudenum)

Question 29

Non essential vs essential

Answer 29

NE: bdy produces
E: needs to find