Unit D - Digestive system Flashcards
How many types of tissue are there? What are they
Four types of tissues Epithelial Connective Muscle Nerve
What are tissues
Groups of cells that work together to carry out a similar function
What does epithelial tissue do
Protects organs, lines body cavities and covers the surface of the body
What does connective tissue do
Provide support and holds various parts of the body together
What does muscle tissue do
Contain special contractile proteins
What does nerve tissue do
Conducts electrical impulses and communicates with the internal and external environment
What are organs
What are organ systems
Groups of tissues that work together
Organ systems are organs working together
What are some examples of organ systems
Respiratory system, excretory system, circulatory system, lymphatic system
What are vitamins? How many essential vitamins are there? What about the solubility of vitamins?
Organic molecules needed in small amounts. 13 essential vitamins. Water-soluble or fat-soluble(Act as coenzymes and antioxidants)
What are minerals
What are they used in
Inorganic molecules needed in small amounts
Bone and tooth formation, as enzyme cofactors, and acid-base balance
What do nutrient deficiency disorders do? Give some examples
Cause a person to have extreme shortages of vital nutrients, vitamins and minerals
Example: anorexia, bulimia
What are nutrients needed for
Fighting infections and cell growth, reproduction, repair
What are the three essential building blocks (nutrients)
Carbohydrates, lipids, proteins
What is the function of carbohydrates
Where are carbohydrates found
Function: energy, storage, structure
Found in bread, corn, rice, potatoes, fruits
Explain the chemistry of carbohydrates
What suffix is used for sugars?
How are Carbohydrates classified
CHO in 1:2:1 ratio (C6H12O6)
“ose”
Classified by the number of carbons they have
What happens when sugars are dissolved in water
They form ring structures
What are monosaccharides?
Give an example
Simplest sugars, contain a single sugar unit, all are isomers of C6H12O6
Example: fructose, galactose
What are disaccharides?
How are they formed
What other molecule is formed during the formation of a disaccharide?
Two monosaccharides
Formed by a dehydration synthesis (dehydrolysis)
A water molecule is formed when two monosaccharides join to form a disaccharide
What is a polysaccharide
How many types are there? What are the types
Union of many monosaccharides, easy to build and easily broken down
2 types, storage and structural
Starch and glycogen are both examples of the storage type of polysaccharides
Explain What types of cells these are used in, And any other information
Starch is used as a plant storage compound. It can be unbranched amylose) or branched (amylopectin)
Glucose is used as an animal storage compound, it is stored in muscles and deliver
Cellulose is an example of the structural type of polysaccharides
What does cellulose do
Component of plant cell walls
What are lipids/fats?
What are they composed of
What do they do
Nonpolar compounds that are insoluble in water
Composed of glycerol and three fatty acids
Store double the energy of carbohydrates
What are lipid/fats needed by the body for
Phospholipid bilayer in cell membranes
Cushions organs
Carriers of vitamin A, D, E, & K
Making hormones
What are triglycerides
Are the bonds stable or unstable
How many types are there, What are they
Another name for lipid/fats
Stable bonds, therefore are hard to break down
Two types: Unsaturated and saturated
What are saturated fats
What state is it at at room temperature
Solid at room temperature, animal fats
What are unsaturated fats
What state is it at at room temperature
Liquid at room temperature
Example: plant oils and fish oils
Talk about the bonds of waxes and the solubility of waxes
What do waxes do
Waxes are stable and insoluble in water
Act as a waterproof coating for plant leaves, bird feathers, and fur
Explain the structure of phospholipids
Have a phosphate group bonded to the glycerol backbone
Have a polar end which is soluble in water and a nonpolar end which is insoluble
What are steroids made from what are they used for?
Made from cholesterol, used to make steroid hormones
How many types of cholesterol are there? what are they
Two types: LDL and HDL
Too much LDL-cholesterol leads to blockages in the arteries
What are proteins used for
Where are they produced
What are the building blocks of proteins
Used as a last source of energy
Produced in the ribosome
Building blocks are amino acids (20 different kinds)
What are the functions of proteins
Structural, receptors, carrier proteins, channel proteins
How many essential amino acids are there that the body can’t make?
How do we get these?
Eight
Must be obtained from food
What determines protein type
How are amino acids joined
What are chains of amino acids called
The order of amino acids
Join together by peptide bonds
Polypeptides
What do polypeptide chains fold into
Alpha helixes, beta-pleated sheets, tertiary structures, quaternary structures
What is protein denaturation
What are some causes of protein denaturation
What happens during protein denaturation
The alteration of a proteins shape
Exposure to heat, radiation, change in pH
The protein will uncoil
It will revert back after the physical or chemical factor is removed
What is coagulation
Permanent change in protein shape
What are enzymes
What do they do
What happens to them during a reaction
Globular proteins, Biological catalyst
Speed up chemical reactions without altering the products formed in the reaction
Remain unchanged reaction and can be reused
What suffix is applied to enzymes
What about the temperature and pH of enzymes
Are enzymes very general and work with everything?
“ase”
Have optimal temperature and pH
Highly specific, each has an active site that provides a match for a substrate
Why are enzymes important
The lower activation energy for reactions (The energy needed to initiate the reaction)
They bring substrate molecules (the reactants) together
They enable reactions to occur at lower temperatures
How do enzymes work
Substrate molecules bind to the active site, forming an enzyme substrate complex
Bonds are broken and new ones are formed
The product is released from the enzyme
What is the induced fit model
When cofactors or coenzymes help enzymes to find the substrate
What are cofactors
What are coenzymes
Inorganic ions such as iron, zinc, and potassium
Organic molecules that are synthesized from vitamins
What factors affect enzyme reaction
PH, substrate concentration, temperature, competitive inhibitors
How does pH affect enzyme reactions
Most enzymes work at an optimal pH
How does substrate concentration affect enzyme reactions
The greater the substrate number, the greater enzyme activity…to a point
How does temperature affect enzyme reactions
If temperature is increased, enzyme activity is increased… Then it drops because of denaturation
How do competitive inhibitors affect enzyme reactions
Have shapes similar to the substrate and competes for active site
Joins to the active site and inhibits the substrate from binding
When does feedback inhibition occur
What type of regulation is this
When the products from chemical reactions interferes with one of the enzymes
Enzyme regulation
When does allosteric regulation occurr
What happens during allosteric regulation
When a proteins function at one site is affected by the binding of a regulatory molecule to a separate site
The entire complex oscillates between the active and inactive form of the enzyme
What is homeostasis
Body systems adjusting in maintaining a constant internal environment despite external environment
What is a stimulant
Increases action on the central nervous system
What is a depressant
Decrease action of the central nervous system
The digestive tract/gastrointestinal tract/alimentary canal is an open ended muscular 26.5–9 m long and adults
Okay
What are the functions of the gastrointestinal tract
Ingestion
Digestion
Absorption
Egestion
What is ingestion
Taking in food
What is digestion
Breaking down complex organic molecules
What is absorption
Move nutrients from the small intestine into the bloodstream
What is egestion
Removal of waste
What are the two types of digestion
Describe each type
Physical: the mechanical process of breaking down food into smaller pieces
Chemical: using enzyme to break down food
What parts of the body are used during ingestion
The mouth, esophagus, the cardiac center, the stomach
How does physical digestion occur? What does this do
What is food chewed into
Physical digestion occurs by the grinding of teeth… It increases the surface area
Food is chewed into bolus (ball)
What do the salivary glands secrete
Mucin and saliva
What does mucin do
Mucin binds food together
What does saliva do
Activate taste buds, lubricate passage of food, dissolve food particles, contains amylase which breaks down amylose (starch) into maltose
What is the esophagus
What does it do
Straight muscular tube that connects mouth to stomach
Lined and secretes mucus
How does food move through the esophagus
Food moves rapidly to the stomach by peristalsis
What is peristalsis
A chain reaction of involuntary smooth muscle contractions
What is the Cardiac sphincter
Where is it located
It is a valve that prevent stomach acid and enzymes from entering the esophagus
Located between the esophagus and stomach
Describe the stomach
How much food can it store
How does it continue physical digestion
What other type of digestion does it begin
Highly elastic, muscular, J shaped sack
Can store about 1.5 L of food
Continues physical digestion by churning
Begins the chemical digestion of proteins
What is the pH of a stomach
One – three
What does the stomach secrete
The stomach contains millions of cells that line and secrete gastric juices
What are some gastric juices
HCl
Enzymes
Mucus
How is HCL made
What does it do
Made by parietal cells
Kills bacteria
Activates Pepsinogen… An enzyme that breaks down protein
How are enzymes made
What do they do
Made by peptic cells
Pepsinogan (inactive form) is converted to pepsin (active form) by HCl and breaks down proteins
How is mucus made
What does it do
Made by mucous cells
Protects the stomach from HCl
What is the pyloric sphincter
The valve that separates the stomach from the small intestine
What is the small intestine
What is chyme? How is it moved
The small intestine is a major site for digestion and absorption
Chyme, from the stomach, is moved by peristalsis
How many sections make up the small intestine? What are they
Duodenum (first section… Digestion)
Jejunum (Second section… Absorption)
Ileum (Third section… Absorption)
Where does most digestion occur
The duodenum
How do enzymes and secretions enter the duodenum
The gal bladder, the pancreas, and intestinal walls
What are the jujenum and ileum used for?
What does villi do?
Absorption of nutrients into the bloodstream and lymphatic system
villi, that contain microvilli, line this part of the small intestine and raise the surface area
What is each villus supplied with
A capillary network and lacteals
What does the capillary network do
What do lacteals do
The capillary network transports monosaccharides and amino acids
Lacteals transports fat
Where is the site of egestion and water absorption
The large intestine (Colon)
What does the large intestine contain
What is at the beginning of the large intestine
contains E. coli bacteria, indigestible wastes, and mucus
At the beginning is the appendix (vestigal structure)
Where does the rectum end
How is a limitation controlled
The rectum ends at the anus
Elimination is controlled by the anal sphincter
What are some accessory organs where no food enters
The liver and pancreas
Describe the liver
Largest glandular organ in the body
Contains four lobes
Produces and secretes bile
How is bile produced, what does it contain, where is it stored, how is it’s release triggered, what does it do to fat
Produced by Liver Contains bile salts Stored in the gal bladder Release is triggered by CCK (hormone) Emulsifies fat in the small intestine (physical digestion)
What happens when fats enter the small intestine
CCK is released
How do bile salts enter the small intestine
CCK triggers the gal bladder to release bile salts into the small intestine
Describe the pancreas
Large elongated gland
Secretes digestive enzymes
Releases sodium bicarbonate
What happens when chyme enters the duodenum
Its acidity causes prosecretin to be converted to secretin
What does secretin do
What does sodium bicarbonate do
Targets the pancreas and signals the release of sodium bicarbonate
Changes the pH from 2 to 9
What happens in carbohydrate digestion
Disaccharides and polysaccharides are broken down into simple sugars
How are disaccharides and polysaccharides broken down into simple sugars
They are broken down by enzymes
What structures release enzymes for Carbohydrate digestion
Mouth, small intestine, pancreas
How are the simple sugars then absorbed
Simple sugars Are then absorbed through the capillaries in the microvilli
What is the only carbohydrate that we can’t digest
Cellulose
Where does lipid digestion occur
What happens during lipid digestion
The duodenum
Fats are emulsified by bile, chemically broken down by lipase, absorbed into the lacteals
What happens in protein digestion
Enzymes break down proteins into amino acids, occurs in the stomach and the duodenum
What structures release enzymes for protein digestion
Stomach, small intestine, pancreas
What happens to amino acids in the bloodstream
Amino acids are absorbed in the bloodstream through capillaries in the microvilli
Most enzymes are secreted in their active form. There are two that are not, what are they?
Trypsinogen
Pepsinogen
What are some disorders
Mumps, heartburn, ulcers, diarrhea, gal stones, cirrhosis
Describe mumps
Can infect many parts of the body, especially the library glands
Describe heartburn
Occurs if the cardiac sphincter does not close properly
Stomach acid enters the esophagus
Explain gastric ulcer
Occurs in the stomach only, usually results from an overgrowth of bacteria
The bacteria damage/break down the mucous lining in the stomach exposing the stomach to HCl
Describe peptic ulcer
Caused by HCL burning the lining in the small intestine or the stomach
Explain diarrhea
Most often caused by bacteria
Affect cells in the large intestine time
The large intestine is not able to absorb water
Runny stools and extreme risk of dehydration
Describe Gallstones
Cholesteryl acts as a binding agent for salt crystals in bile
The crystals can precipitate and form gal stones, which block the bile duct
The bile enters the bloodstream and causes jaundice; yellow skin
Describe cirrhosis
Alcohol is a poison that overtime can destroy liver and cells
Damaged liver cells are replaced by fibrous connective tissue, which are not able to carry out normal liver functions
Gastric juices are secreted in response to what stimuli?
Sight, smell, taste, swallowing
What is gastrin? What does it do? When is it released
A hormone
Stimulates the release of HCl
Released when there is partially digested proteins in your stomach
What is enterogastrone
What does it do
When is it released
Hormone that slows peristalsis and is released when there are fats in the small intestine
What does an ultrasound do
Uses soundwaves to create an image
Why is it important to increase the surface area of the small intestine
So you can absorb more nutrients
