Digestion and Carbohydrates Flashcards
The process by which food is broken down into absorbable units is called
digestion
The uptake of nutrients by the cell in the small intestine for transport is called:
absorption
The flexible muscular tube that extends from the mouth through the esophagus, stomach,
small intestine, large intestine, and the rectum to the anus is called
gastrointestinal tract
The process of digestion begins in the
mouth
The process of chewing is called
mastication
After a mouthful of food has been swallowed, it is called:
bolus
To keep food from entering the lungs, the ______ closes off air passages.
epiglottis
The wavelike muscular contractions that propel food through the digestive tract are called:
peristalsis
The partially digested food that enters the small intestine from the stomach is called:
chyme
An enzyme that hydrolyzes proteins is called:
protease
The main function of bile is to:
emulsify fats
Nutrients that are digested in the small intestine are:
carbohydrates, fat, and protein
A narrow sac extending from the beginning of the colon is called the
appendix
A single villus is composed of hundreds of ______, each covered with ______.
cells; microvilli
Avoiding certain food combinations at the same meal is:
foolish because the body is equipped to handle digestion of a variety of foods and food types
A periodic squeezing of the intestines is:
segmentation
The strength of acids is measured in:
pH units
living microorganisms found in foods that benefit health are called:
probiotics
Waste matter discharged from the colon is:
stools
Saliva contains:
salts, carbohydrases, and water
The lymphatic system:
eventually drains into the blood circulatory system and collects in a large duct behind the heart
What hormone is released in the presence of fat that slows intestinal motility to allow a longer digestion time?
Cholecystokinin (CCK)
duodenum
first part of the small intestine
ileum
the final and longest segment of the small intestine
jejunum
part of the small intestine lying between the duodenum and the ileum
sphincter
circular muscles that serve as valves to open and close certain parts of the body
lumen
inside space of a tubular structure, such as an artery or intestine
GI motility
the spontaneous movement of the GI tract that aids in the digestion and transit of the contents within it
transit time
how long it takes for food to travel through the digestive tract
reflux
a backward flow
villi
fingerlike projections from the folds of the small intestine
microvilli
tiny, hairlike projections on each cell of every villus that can trap nutrient particles and transport them into the cells
crypt
tubular glands that lie between the intestinal villi and secrete intestinal juices into the small intestine
goblet cells
a column-shaped cell that secretes the main component of mucus
circulatory system
system that circulates blood and lymph through the body, consisting of the heart, blood vessels, blood, lymph, and the lymphatic vessels and glands
homeostasis
the maintenance of constant internal conditions (such as blood chemistry, temperature, and blood pressure) by the body’s control systems
peptic ulcer
erosion of the stomach lining caused by drugs, alcohol, or a bacterium
IBS
a disorder of bowel function caused by hypersensitivity to stimuli in the large intestine
celiac disease
a disease in which the small intestine is hypersensitive to gluten, leading to difficulty in digesting food
bloating
A buildup of gas in the stomach and intestines
fodmap
short chain carbohydrates that are poorly absorbed in the small intestine and are prone to absorb water and ferment in the colon
gut microbiota
the microorganisms, including bacteria and archaea, that live in the digestive tracts of vertebrates
CCK
a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat and protein
bile
a fluid that is made and released by the liver and stored in the gallbladder
sodium bicarbonate
used to relieve heartburn, sour stomach, or acid indigestion by neutralizing excess stomach acid
mucus
viscous fluid that moistens, lubricates, and protects many of the passages of the digestive and respiratory tracts in the body
HCl
helps your body to break down, digest, and absorb nutrients such as protein
salivary amylase
glucose-polymer cleavage enzyme that is produced by the salivary glands
pancreatic amylase
Any of a class of enzymes that split or hydrolyze starch
mouth in digestion
- Begins breaking up food by mastication
* CHOs begin digestion here
pharynx in digestion
carries air, food and fluid down from the nose and mouth
trachea in digestion
carries air to the lungs
esophagus in digestion
contracts as it moves food into the stomach
LES in digestion
allows food transit from the esophagus into the stomach and prevents the reflux of gastric contents back into the esophagus
stomach in digestion
stomach muscles churn food and acids help to break food down before it moves into the small intestine
-digests proteins
pancreas in digestion
makes hormones and pancreatic juices called enzymes that break down sugars, fats, and starches
small intestine in digestion
food is broken down into liquid and most of its nutrients are absorbed
-lipids are digested
large intestine in digestion
turns food waste into stool and passes it from the body
Where does segmentation take place and functions does segmentation have?
- small intestine
- separates chyme and then pushes it back together, mixing it and providing time for digestion and absorption
What is the role of saliva?
-to ease swallowing down the esophagus, also protects teeth and linings of the mouth, esophagus and stomach
Describe the role of the gastric juices in the stomach. How does this aid in digestion?
gastric juices are added to food in the stomach to form chyme, makes it easier to pass to the duodenum
What part of the GI tract do pancreatic juices get secreted into? Why are they important?
- They empty into the upper part of your small intestine called the duodenum
- they break down foods
What type of molecule is an enzyme? What is the function of an enzyme?
- protein
- help speed up chemical reactions in the human body
How do probiotics and prebiotics
aid in digestive health?
- helping to alleviate diarrhea, constipation, inflammatory bowel disease, ulcers, allergies, lactose intolerance, and infant colic
- enhance immune function and protect against colon cancer
There are three types of nutrient absorption. Name all 3 and briefly describe how they work
- active transport: the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy
- passive diffusion: process by which molecules diffuse from a region of higher concentration to a region of lower concentration
- facilitated diffusion: molecules diffuse across the plasma membrane with assistance from membrane proteins
Why are villi on the small intestine so important?
increase the internal surface area of the intestinal walls making available a greater surface area for absorption
Identify the routing of blood leaving the digestive system. Explain why blood leaving the
intestines travels first to the liver.
Blood leaves the digestive system by VEIN. The hepatic portal vein directs blood to the liver because it returns it to the heart. The livers placement ensures that it will be the first to receive nutrients.
Identify the nutrients that leave the digestive system by the lymphatic system.
large fats and fat soluble vitamins
Know Issues with Digestion and how to prevent/treat them:
a. Heartburn/GERD
b. Choking
c. IBS
d. Peptic Ulcer
a. - HCl from stomach into esophagus
- § Treatment- dietary changes, behavior modification, OTC antacids or Rx drugs, or surgery in very severe cases
b. § Slow down and chew food
c. ○ Treatment
Dietary modification, stress management, and occasional use of prescription drugs
d. ○ Treatment
§ Avoid irritating foods, Rx
carbohydrate
sugar molecules
monosaccharide
one sugar molecule
disaccharide
two sugar molecules linked together
polysaccharide
more than 10 sugar molecules linked together
glycogen
a storage form of glucose manufactured and stored in the liver and muscles
dietary fiber
found naturally in foods
satiety
a state of noneating, characterized by the absence of hunger, which follows at the end of a meal and arises from the consequences of food ingestion
resistant starch
a type of carbohydrate that doesn’t get digested in your small intestine
lactose intolerance
Inability to digest lactose
gluconeogenesis
making of glucose from noncarbohydrate sources such as amino acids or glycerol
Protein-sparing action
the process by which the body derives energy from sources other than protein
ketosis
process that happens when your body doesn’t have enough carbohydrates to burn for energy. Instead, it burns fat and makes things called ketones, which it can use for fuel
insulin
a hormone secreted by special cells in the pancreas in response to elevated blood glucose concentration
glucagon
a hormone secreted by the pancreas in response to low blood glucose concentration
diabetes
a metabolic disorder characterized by elevated blood glucose levels resulting from insufficient insulin production
hypoglycemia
A blood glucose less than 60 mg/dL
dental caries
diet-dependent infectious disease primarily attributed to the presence of oral bacteria
artificial sweeteners
sugar substitutes that provide negligible, if any, energy; sometimes called nonnutritive sweeteners
sugar alcohol
a type of sweetener used in foods labeled “sugar-free”
Which cells in the body use glucose?
brain, nerves, red blood cells
“Sugars” are composed of what molecules?
CHO
List the 3 monosaccharides and two important features of each.
-glucose
○ Blood sugar
-fructose
○ Fruits and vegetables/honey/high fructose corn syrup
○ Sweetest
-galactose
○ Dairy foods
List the 3 disaccharides. Which monosaccharides make up each disaccharide? What foods are
associated with each disaccharide?
• Maltose ○ Glucose and glucose beer and molasses • Sucrose ○ Glucose and fructose apples and carrots • Lactose ○ Glucose and galactose milk and yogurt
Glycogen is composed of many ___________ molecules. Where do we find glycogen? Is it
primarily a storage molecule or dietary molecule?
- glucose
- the liver and muscles
- storage
Starch is also composed of ___________. Starch is the storage form of carbohydrate for what?
What foods have starch?
- glucose
- plants
- potatoes, bread, pasta
Fiber is found where? What is the role of fiber? What is the recommendation for fiber
consumption?
- whole grains, beans, fruits, and vegetables
- helps regulate the body’s use of sugars, helping to keep hunger and blood sugar in check
- 25-30g/day
Name and describe the different types of fibers. Name some food sources of the different
types of fiber.
□ Soluble fiber-dissolves in water, viscous
® Fruits, vegetables, beans, and oats
□ Insoluble water-does not dissolve in water
® Seeds, whole grains, and some fruits and vegetables
What specific enzymes are required for carbohydrate digestion?
-amylase, maltase, lactase
What are options for those who suffer from lactose intolerance?
○ Consuming smaller amounts of dairy at a time
○ Eating dairy foods with a meal or snack
○ Choosing lower lactose foods
Can we make glucose from other nutrients in the body?
glucose can be synthesized from amino acid molecules
Describe what happens in the body with gluconeogenesis and ketosis. What is the minimum
amount of carbohydrate you need in your body to spare protein breakdown?
-ketosis: • 1st- use glycogen stores • 2nd-Start using protein to make Glucose ○ Gluconeogenesis • 3rd-use alternative fuel (ketones) ○ Ketones-incomplete fat breakdown § Ketone bodies -50-100g
Why is it important to maintain a steady blood glucose level? What happens if we don’t?
It’s important to keep your blood sugar levels in your target range as much as possible to help prevent or delay long-term, serious health problems, such as heart disease, vision loss, and kidney disease
What two hormones regulate blood glucose? How do they do this?
- Insulin and glucagon
□ Insulin: hormone
® When BG is high, it signals to move glucose into cell
® Causes blood glucose to go down
® Made in the pancreas by specialized cells called beta-cells
□ Glucagon: hormone
® When BG is low, it signals glycogen to break apart into glucose
® Causes blood glucose to go up
® Signals to make glucose from protein
® Produced by the alpha cells in the pancreas
What is the normal level for fasting blood glucose ?
70-99mg/dl
What do we mean by “added sugar”. (what is the definition)?
are added during the processing of packaged foods and do not provide any nutrients
What is the recommendation for added sugar? Name some ingredients you would see on a
food label that would be considered added sugar.
-50g/day
-agave nectar.
brown sugar.
cane crystals.
cane sugar.
corn sweetener.
corn syrup.
crystalline fructose.
dextrose.
Where is fructose metabolized? What happens when we consume large amounts of fructose
and how does this impact blood lipids levels or your risk of chronic diseases?
- the liver
- the liver gets overloaded and starts turning the fructose into fat
- very high fructose intake (>100 g/d) increases serum LDL-C and TC concentrations
Name some artificial sweeteners – the more common ones found in food products as
discussed in class. What are some benefits to using artificial sweeteners? Are there risks
associated with using artificial sweeteners?
○ Saccharin ○ Aspartame ○ Acesulfame K ○ Neotame ○ Sucralose - Less kcals Do not cause cavities Do not impact blood sugar
-no, determined safe
