Module 3

Question 1

How are nutrients delivered to the liver?

Answer 1

nutrients that enter the blood capillaries at the villi will then enter veins that lead to liver.

at liver, material is stored, used, detoxified, or sent off to the rest of the system

material that enters the cardiovascular system can then be transported to where it is needed

Question 2

How do glucose and amino acids enter the blood/lymph?

Answer 2

through active transport

Question 3

How do lipids, fats, and soluble vitamins enter the blood/lymph ?

Answer 3

passive diffusion

Question 4

How does food pass through the esophagus ?

Answer 4

no active digestion or absorption

peristalsis occurs

Question 5

How does food pass through the pharynx?

Answer 5

pharynx aka the throat, the common passageway for food and inspired air

no active digestion or absorption

epiglottis directs food from pharynx into esophagus instead of down the wrong tube into trachea

Question 6

How does food pass through the stomach ?

Answer 6

• temporary reservoir for food
• food remains for 4-5 hours
• 3 layers of muscles allow stomach to churn
• lower esophageal sphincter and pyloric sphincter close as stomach churns food nd mixes it with gastric juice.
• when food leaves stomach it is in a semi-liquic form called chyme

Question 7

How does fructose enter the blood/lymph ?

Answer 7

through facilitated diffusion

Question 8

How does glucose metabolism work ?

Answer 8

1. glycolysis : breakdown of glucose (glucose to pyruvate + ATP)
2. breakdown of pyruvate : depends on whether oxygen is present (aerobic, acetyl coA formed) or not (anaerobic, lactate and ATP)
3. citric acid cycle : acetyl CoA combines with oxaloacetate to produce CO2, H2O, ATP, and electron transporters
4. electron transport chain : electrons are exchanged between the electron transporters and membrane bound proteins. leads to a build up of protons on one side of the membrane. protons get moved through a protein pump. produces more than 30 molecules of ATP.

Question 9

How does the condensation reaction occur ?

Answer 9

binding of molecules into longer chains of molecules. water is liberated in the process. binding of amino acids into a specific chain begins process of protein synthesis

Question 10

How does the mouth pass food?

Answer 10

• teeth rip food apart
• tongue pushes food towards teeth and mixes it with saliva
• salivary glands secrete saliva into mouth which contains: salivary amylase, lingual lipase digests lipids, mucus lubricates food, lysozyme = antibacterial substance that disinfects food
• when food leaves the mouth it is a bolus

Question 11

How does water enter the blood/lymph?

Answer 11

osmosis

Question 12

How long does it take for material to pass through entire digestive tract ?

Answer 12

2+ days

food spends most time in large intestine

Question 13

How should you dislodge an object that enters the airways and causes choking ?

Answer 13

1. support choking persons upper body so they can lean forward with support.
2. apply 5 sharp blows between shoulder blades using the heel of the hand.
3. if blockage not cleared, place fist above belly button and use other hand to grasp the fist.
4. press into abdomen and in an upward motion.
5. forcefully make a J shape 5 times.
6. if blockage remains, repeat.

Question 14

What are gallstones?

Answer 14

hardened bile deposits that form stones in the gallbladder.

can be extremely painful when fat is consumed and gallbladder contracts to release bile

Question 15

What are hormones ?

Answer 15

hormones are chemical messengers that are required for many physiological processes including digestion.

they are released from one area of the body and travel through the blood to different parts of the body

Question 16

What are prebiotics?

Answer 16

carbohydrates that act as food for microbiota

supports the health of the microbiome

Question 17

What are probiotics?

Answer 17

cultures of living organisms

Question 18

What are the 2 types of digestion?

Answer 18

mechanical/physical: uses physical process such as chewing to break food apart

chemical digestion: uses enzymes to alter the chemical structure of nutrients

Question 19

What are the 3 sections of the small intestine ?

Answer 19

duodenum, jejunum, ileum

Question 20

What are the accessory structures of the digestive tract ?

Answer 20

liver, gallbladder, pancreas.

they secrets material into the duodenum of the small intestine

Question 21

What are the layers of the digestive tract wall from the inside out ?

Answer 21

lumen, mucosa, nerve plexus, submucosa,nerve plexus, muscularis, serosa

Question 22

What are the parts of the digestive system ?

Answer 22

mouth, pharynx, esophagus, stomach, liver, gallbladder, pancreas, small intestine, large intestine

Question 23

What are ulcers?

Answer 23

weakened, damaged parts of the lin in of the digestive tract

(canker sores, peptic ulcers)

Question 24

What do the liver and gallbladder do ?

Answer 24

liver makes bile and the gallbladder stores it.

Question 25

What does the pancreas secrete?

Answer 25

pancreatic juice: digestive enzymes: amylase, lipase, proteases bicarbonate: neutralizes chyme

Question 26

What happens in the large intestine ?

Answer 26

unabsorbed material is packaged for removal or acted upon by bacteria.

Question 27

What is amino acid metabolism ?

Answer 27

amino acid—> deamination (nitrogen group removed from amino acid)—> produces pyruvate, acetyl CoA, citric acid cycle intermediates. there are 21 amino acids, each w unique side chain. (21 possibilities for what remains)

Question 28

What is anabolism ?

Answer 28

smaller molecules come together to form larger ones require input of energy

Question 29

What is beta oxidation (lipid metabolism) ?

Answer 29

splits the fatty acid, 2 carbon atoms at a time. each 2 carbon molecule of a fatty acid can be used to form acetyl CoA.

Question 30

What is bile?

Answer 30

liquid emulsifier that breaks larger lipid globules into smaller ones and allows them to be suspended in a watery environment

Question 31

What is catabolism?

Answer 31

larger molecules are broken down into smaller ones leads to a net release of energy

Question 32

What is cellular respiration ?

Answer 32

catabolism of energy of the energy-yielding nutrients leading to the production of ATP primarily occurs in the mitochondria metabolic pathway

Question 33

What is constipation?

Answer 33

bowel movements that are difficult to pass or less frequent. stool tends to be dry, hard, and can be painful to pass increases risk for hemorrhoids risk factors: age, female sex, genetics, physical inactivity, diet low in fruits, vegetables, and water

Question 34

What is diarrhea?

Answer 34

occurs when matter passes too quickly through the large intestine stools are loose and have liquid like consistency typically due to bacteria and viral infections

Question 35

What is digestion?

Answer 35

separation of nutrients in food and breaks larger molecules into smaller ones so they can be absorbed polysaccharides—> sugar triglycerides—> fatty acids proteins—> amino acids

Question 36

What is diverticula and diverticulitis?

Answer 36

diverticula : weakened walls of large intestine that forms outpouchings can become diverticulitis when inflamed age, smoking, obesity, physical inactivity can increase risk

Question 37

What is found in the large intestine ?

Answer 37

larges population of non-human cells: microbiota (mostly bacteria. 300-500 different species). roles: - vitamin synthesis - energy harvesting - health/disease - appetite

Question 38

What is gastric juice made of ?

Answer 38

mucus, gastric lipase (breaks down lipids), hydrochloride acid (unravels proteins, activates pepsinogen), pepsinogen (becomes pepsin, which digests protein)

Question 39

What is gastroesophageal reflux ?

Answer 39

when lower esophageal sphincter weakens and acidic stomach contents spill into esophagus (heart burn) can lead to gastroesophageal reflux disease which can lead to ulcers

Question 40

What is IBS?

Answer 40

irritable bowel syndrome. unknown cause symptoms include abdominal pain, bloating, cramping, diarrhea, constipation, flatulence treatments focus on alleviating symptoms: avoiding trigger foods, managing stress, drinking plenty of fluids

Question 41

What is ketogenesis?

Answer 41

on a very low carb diet, fatty acids cannot enter citric acid cycle, and instead form ketones. (citric acid cycle requires carbohydrates)

Question 42

What is metabolism ?

Answer 42

sum of chemical reactions that occur in our bodies

Question 43

What is peristalsis ?

Answer 43

type of movement that occurs in esophagus among other areas. circular smooth muscle contract behind food in a wave like fashion, pushing it forward through the digestive tract relaxation of the muscle in from of the bolus opens a path for the food to be pushed down.

Question 44

What is the hydrolysis reaction ?

Answer 44

input of water helps to break down the molecules.

Question 45

What is the main functional unit of the small intestine ?

Answer 45

villus or villi plural. villi are invaginations of the small intestine wall. cells on their surface have extensions called microvilli (known as brush border) which secrete enzymes. nutrients subunits are absorbed into the centre of the villus where they then enter the blood or the lymph

Question 46

What is the main part of the large intestine ?

Answer 46

the colon

Question 47

What is the microbiome ?

Answer 47

genetic material of non-human organisms found in body

Question 48

What is the primary site of digestion and absorption ?

Answer 48

small intestine

Question 49

What is the purpose of enzymes?

Answer 49

speeds up the rate of reaction and provides a location for chemical reactions to occur enzymes can participate in hydrolysis and condensation reactions.

Question 50

When we consume more energy than we need, where is the excess energy stored?

Answer 50

as lipid i our fat tissue

Question 51

Describe the process of emulsification of lipids

Answer 51

1. Large lipid globules cannot suspend within the watery environment of small intestine. They are also too large for the enzyme lipase to act on 2. The liver and gallbladder secrete bile into the small intestine when lipids are present 3. Bile's hydrophobic tails arrange themselves to face the lipid, the heads arrange themselves to face the watery lumen 4. Larger lipid globules are broken into smaller lipid droplets surrounded by bile. This structure is called a micelle. 5. Micelles allow lipids to be suspended within and freely move around the small intestine lumen. They also allow lipase to act on lipids