Nutrients and Digestion Flashcards
What are nutrients?
Nutrients are chemicals in the food you eat that help your body perform all its functions.
What are the six nutrients?
- carbohydrates
- proteins
- fats
- vitamins
- minerals
- water
What are macronutrients? Which nutrients are macronutrients?
Macronutrients are the nutrients needed daily in large quantities. Macronutrients: carbohydrates, fats, proteins, and water.
What are micronutrients? Which nutrients are micronutrients?
Micronutrients are the nutrients needed in small amounts that help your body perform chemical reactions. Micronutrients: vitamins, minerals
Function of carbohydrates (polysaccharides)
- provide materials to build cell membranes
- provide quick energy for use by cell
Examples of carbohydrates
- Starch
- Glycogen
- Cellulose
- Chitin
Function of lipids (triglycerides)
- store energy reserves for later use by cells
- cushion and insulate internal organs
- provide materials to build cell membranes
Types of lipids
- saturated
- unsaturated
- trans fat
Function of proteins
- provide structure and support for blood cells, body tissues, and muscles
- aids in muscle movement (ex. contractions)
- acts like a catalyst to speed up chemical reactions in the cell
- provides immunity against infections and diseases
- transports ions in cell membranes
Examples of proteins
- insulin
- hemoglobin
- collagen
- antibodies
- ** enzymes **
Function of vitamins
* vitamins are organic *
- supports enzyme function
- transports O2 (oxygen)
- releases energy
- heal wounds
- helps with the growth of bones and muscles
- boosts immune system
Function of minerals
* minerals are inorganic *
- build materials for our bones
- influence muscle and nerve function
- regulate the body’s water balance
- helps with making sure the bones, muscles, heart, and brain are working properly
What are the 4 components of DIGESTION? (explain each one)
- ingestion - the consumption or taking in of nutrients
- digestion - the chemical breakdown of large organic molecules into smaller components by ENZYMES
- absorption - the transport of digested nutrients to body tissues
- egestion - the elimination of food waste materials from the body
What do all macronutrients need to be broken down to so that they can be absorbed by the intestinal cells?
individual monomers
What absorption process is responsible for all macronutrients breaking down into individual monomers?
diffusion
What are enzymes?
Enzymes are proteins that help speed up chemical reactions in our bodies. This is why they’re called “biological catalysts”.
What are the 4 categories for digestive enzymes?
- carbohydrases
- proteases
- lipase
- nucleases
What is an enzyme’s special binding area called
the active site
What binds to the active site and gets broken apart?
a substrate molecule
explain carbohydrases (what breaks down into what?)
- disaccharides - maltose, sucrose, lactose *
Starch is broken down into disaccharides (double sugars) by SALIVARY AMYLASE
Maltose is broken down to glucose + glucose by MALTASE
Sucrose is broken down to glucose + fructose by SUCRASE
Lactose is broken down to glucose + galactose by LACTASE
This process takes place in the DUODENUM!!!!
explain proteases (what breaks down into what? )
Large protein is broken down into smaller polypeptides by PEPSIN (in the stomach)
Smaller polypeptides are broken down into small peptides by TRYPSIN (pancreas)
Small peptides are broken down into amino acids by EREPSIN (pancreas)
explain lipases (what breaks down into what? )
Triglycerides - the fat gets emulsified into small droplets by BILE not an enzyme (from the gall bladder)
These small droplets (still triglycerides) are broken down into glycerol + fatty acids by LIPASE (pancreas)
Why are teeth used for mechanical breakdown for food?
For an increased surface area that allows for easier chemical digestion.
What covers the trachea (airway) while food is being swallowed to ensure that the food enters the esophagus and to prevent choking?
epiglottis
What is peristalsis?
Peristalsis is the involuntary contractions that move food/the bolus of food through the esophagus and throughout the gastrointestinal tract.
What organs are involved in the digestive system?
- Mouth
- Esophagus
- Stomach
- Small intestine
- Pancreas
- Liver
- Large intestine
What are the two main functions of the stomach?
- stores food
- chemical digestion
The stomach is lined with smooth muscles called _____ which allow the stomach to expand and _____ for protection.
rugae; mucus
What is chyme?
Chyme is a liquified paste of food bolus
- the food bolus gets changed into chyme after physical and chemical digestion.
How is the movement of food controlled?
The movement of food into and out of the stomach is controlled by sphincters.
Cardiac sphincter (top of stomach): allows food from the esophagus to enter and prevents food from going back up into the esophagus
Pyloric sphincter (bottom of stomach): slowly releases chyme into the small intestine
What do the gastric fluids in the stomach consist?
Mucus, hydrochloric acid, pepsinogen (inactive)
How is an ulcer caused?
An ulcer is when there is a sore in the stomach due to the mucus lining being broken down by Heliobacter pylori or chronic high acidity.
What is the pH range of the stomach?
Between 2.0 - 3.0
What happens in the small intestine?
Digestion of carbohydrates, proteins, lipids, AND the absorption of nutrients.
What are the 3 sections of the small intestine?
- Duodenum (most of the digestion occurs here)
- Jejunum
- Ileum
What produces hydrochloric acid in the stomach?
parietal cells
What transports absorbed fatty acids to the bloodstream?
Lymphatic vessel
What organ absorbs water and vitamin K?
Large intestine
What is the small intestine lined with? Why is it lined with this?
It is lined with villi to increase surface area to absorb digested nutrients.
What surrounds each villus and further helps with the increase in surface area for nutrient absorption?
microvilli
What are digested fat monomers absorbed into?
Digested fat monomers are absorbed into LACTEAL (a lymphatic vessel) and eventually enter the blood.
What organ produces digestive enzymes that act on foods in the small intestine?
pancreas
What organ produces the hormone insulin and glucagon which regulates blood sugar levels?
pancreas
What stimulates the conversion of prosecretin hormone (inactive form) into secretin (active form) which acts on the pancreas?
the chyme
What enzymes are included in the pancreatic fluid?
- trypsin
- erepsin
- amylase
- lipase
What are some important functions of the liver?
- synthesis
- breakdown/conversion
- storage of glycogen, vitamins A, B12, D
- detoxification
What does the liver produce and where is this thing stored?
The liver produces BILE that digests fats. It is stored and concentrated in the GALLBLADDER.
How does the liver detoxify substances?
It makes the substances soluble which are then dissolved in the bloodstream and eliminated in urine.
What are the two main functions of the large intestine?
- absorption of water
- storage of undigested waste products
What are the parts of the large intestine?
starts with the ileocecal sphincter
Parts:
- cecum
- colon
- rectum
- anus
Bowel movements force solid waste called feces to pass through the ______ and exit the body through the ______.
rectum; anus
What does fiber help with?
Fiber helps to remove wastes and toxins from the body.
What is Crohns disease (ulcerative colitis)?
CR: a form of inflammatory disease that can affect any part of the alimentary canal (gastrointestinal tract) from the mouth to the anus
Ulcerative Colitis: a form of inflammatory disease that attacks the colon
symptoms: diarrhea, fever, fatigue, bloody stools, weight loss
treatment: medication, diet changes, surgery
Which macromolecule is not chemically digested in our food and acts like a fiber?
Cellulose
What nonessential organ sometimes becomes inflamed or ruptures and needs to be removed?
Appendix
What hormone stimulates pancreatic secretions?
secretin
What macromolecule is the primary source of energy?
Carbohydrates
Which organ does the hormone CCK (cholecystokinin) act on?
- Gallbladder (& pancreas)
What secretes the fluid that begins digestion of starches?
Salivary glands
What contains villi and microvilli?
Small intestine
BENEDICT TEST: What is present when the solution goes from blue to orange?
reducing sugars aka CARBOHYDRATES (ex. glucose, fructose, maltose, lactose)
LUGOLS IODINE TEST: What is present when the solution is blue/black?
Starch
BIURET TEST: Is there anything present when the solution is light blue?
No
*** If proteins are present, the solution will go from light blue to purple.
What is lactose intolerance?
a common digestive problem where the body cannot digest lactose ( a sugar found in milk and dairy products)
symptoms: bloated stomach, nausea, diarrhea, cramps
treatments: lactose enzyme tablets, diet changes
What is liver cirrhosis?
- severe scarring of the liver (it is irreversible as the healthy liver tissue gets replaced with non-functioning scar tissue)
symptoms: fatigue, easy bleeding, nausea, loss of appetite, swelling
treatment: treatment for alcohol dependency, weight loss, medication
What is constipation?
When bowel movements are reduced to 3 per week or less (stools are dry, small and difficult to eliminate)
symptoms: bloated, weakness, painful bowel movements
treatment: eating high fiber diets, drinking water, exercising, laxatives
What is colon cancer?
a growth of cells that begin in a part of the large intestine called the COLON
symptoms: change in bowel movements, diarrhea, constipation, bloody stool, weakness
treatment: surgery, radiofrequency ablation, cryosurgery, chemotherapy, etc.
What is diabetes?
a condition where the body is unable to use glucose for energy
symptoms: urinating a lot, thirst, weight loss, hunger, numbness, blurry vision, etc.
treatment: taking insulin (or other diabetes medicine), healthy food + beverage choices, physical activity, enough sleep, etc.
What is gastroesophageal reflux disease (GERD)?
common condition where the stomach contents move up into the esophagus
symptoms: heartburn, backwash, trouble swallowing, chest pain
treatment: antacids, H2 blockers, proton pump inhibitors, endoscopy, etc.
How does an enzyme like amylase break down nutrients?
An enzyme like amylase breaks down nutrients by binding to the respective substrate. Salivary Amylase binds to starch and breaks it down into disaccharides (double sugars) - maltose, sucrose, and lactose.
In order for the breakdown to occur, the enzyme must fit perfectly into its substrate. Factors like temperature and acidity are important as they affect the enzyme’s function. Changes in the optimal temperature and pH (acidity) can cause the enzyme to denature.
How are nutrients absorbed into the blood and explain how this structure is especially suited for the function of nutrient absorption.
remember the diagram
HAPPENS IN THE SMALL INTESTINE - VILLUS*
AMINO ACIDS and MONOSACCHARIDES (glucose) are absorbed directly into the blood vessel by FACILITATED diffusion (proteins assist in their transport).
Glycerol and fatty acids are absorbed into the LACTEAL (lymphatic vessel) by SIMPLE DIFFUSION (no assistance required)
