digestive system - grosse pointe public schools · >the digestive system increases the surface...
TRANSCRIPT
![Page 1: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/1.jpg)
WedNesday October 24th 2012
• QU: What would happen if an organism stopped eating?
• OBJ: Digestive System Notes
Digestive SystemAll about hydrolysis and surface area
The Digestive System: Basics
• All organisms need energy to survive
> Use energy to reproduce, grow, and repair
How do we get that energy?
![Page 2: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/2.jpg)
The Digestive System: Basics
• Four parts to digestion:
> Ingestion
> Digestion
> Absorption
> Elimination
The Digestive System: Basics
• Stage 1: Ingestion
> The act of eating or taking in food
> Different organisms do this in different ways
– Suspension feeders
– Carnivores, herbivores
The Digestive System: Basics• Stage 2: Digestion
> Breaking down food into molecules small enough for the body to absorb
> Uses water to break down the molecules…What type of reaction is this?
– Hydrolysis
![Page 3: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/3.jpg)
The Digestive System: Basics• Stage 2: Digestion
• Breaking polymers to monomers
> Nucleic Acids to
> Carbohydrates to
> Protein to
> Lipids to
Nucleotides
Monosacharides
Amino Acids
Fatty Acid & Glycerol
Why is it important to break down these large molecules into smaller ones?
We are made up of tiny things called CELLS‐they can only work with tiny nutrients.
Review of Hydrolysis
The Digestive System: Basics
• Stage 2: Digestion
• Occurs in 2 ways:
> 1. Mechanical Digestion:
> starting with our teeth any sloshing or churning that moves the food
![Page 4: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/4.jpg)
The Digestive System: Basics
• Stage 2: Digestion
• Occurs in 2 ways (cont.):
> 2. Chemical Digestion:
> catalyzed by specific enzymes, hydrolysis breaks the chemical bonds by adding water
Main Goals of Digestive System
• 1. Digestion: Change food we eat into chemical nutrients
a. mechanical digestion changes big pieces into small, solids into liquids
b. chemical digestion changes big molecules into small (e.g., starch into sugar)
‐Breaks bonds
2. Absorption: Move nutrients into blood stream
The Digestive System: Basics
• Stage 3: Absorption
• Cells lining the digestive tract take up small nutrient molecules (monomers)
> then they travel to the blood and around the body for usage
![Page 5: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/5.jpg)
The Digestive System: Basics• Stage 4: Elimination
• Undigested material passes out of the digestive tract.
The Digestive System: Basics
• The keys for success:
> Water for hydrolysis
> Breaks the polymers into usable monomers
> Surface area
> The digestive system increases the surface area or workable area
– The larger the workable area the faster the digestion and absorption
The Digestive System: Basics• Food enters through alimentary canal:
> Tube from mouth down to anus
> Every organ that food passes through
![Page 6: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/6.jpg)
The Digestive System: Basics• Alimentary Canal:
> Mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus
The Digestive System: Basics• Accessory Organs:
> Aid in digestion but food doesn’t pass directly through them.
> liver, pancreas, salivary glands, gallbladder, tongue
– The organs in red all secrete enzymes that aid in digestion
![Page 7: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/7.jpg)
The Digestive System: Basics
• How do enzymes help with digestion?
> They lower activation energy
> Allowing for faster digestion of food
Tuesday October 23rd 2012
• QU: Describe how hydrolysis relates to the digestive system.
• OBJ: Continue Digestion Notes and Lab
“The length of the digestive system is about 20‐30 feet long”
The Digestive System
• Yesterday we said that the two keys to the digestive system were?
> Hydrolysis: adding water to break bonds
> Surface area: Increasing the workable area for an organism.
![Page 8: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/8.jpg)
Digestive System• Today we are going to look at the order of the organs and their names.
Mouth, Pharynx,
Esophagus, and StomachChapter 29
Ms. Dalby
The beginnings
• Ingestion
> Food into the mouth…
> What occurs next?
![Page 9: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/9.jpg)
The Mouth• Mechanical: Teeth and tongue
> Teeth chomps up food
> Exposes more surface area
> Easier to swallow
> Tongues swirls food and saliva together
> Yummmmmm
The Mouth• Chemical:
> Salivary Glands
> Secrete Saliva
– Contains Digestive enzymes
– Mucus
– Other chemicals
– Water
The Mouth• Breaking Down Saliva
> Enzymes
> Amylase
– Starch to Sugar (Polysaccharides to Monosaccharides)
> Other Chemicals
> Kill bacteria, neutralize acids (protect your teeth)
> Mucus:
> Slippery secretion that protects cells
![Page 10: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/10.jpg)
Mouth: Beginning à End
• Carboyhdrates à Disacharides (Chemical)
• Proteins à Smaller Polypeptides (Mechanical)
• Nucleic Acids àSmaller Nucleic Acids (Mechanical)
• Lipids à Smaller Lipids (Mechanical)
*Once food is mixed with saliva is called BOLUS*
Pharynx• Upper portion of the throat
• Junction between alimentary canal and airway
> Epiglottis functions to cover airway
> Ensures food enters “correct tube”
Pharynx: Beginning à End
• Disaccharides à Disaccharides (Chemical)
• Small Polypeptides à Smaller Polypeptides (Mechanical)
• Small Nucleic Acids àSmaller Nucleic Acids (Mechanical)
• Small Lipids à Smaller Lipids (Mechanical)
*Food still called Bolus*
![Page 11: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/11.jpg)
Esophagus• Muscle‐encased tube
• Walls secrete mucus to help with movement and protect walls
• Will work against gravity
> Peristalsis
> Swallowing begins voluntary then to involuntary with peristalsis
Esophagus: Beginning à End• Disaccharides à Disaccharides(Chemical)
• Small Polypeptides à Smaller Polypeptides (Mechanical)
• Small Nucleic Acids àSmaller Nucleic Acids (Mechanical)
• Small Lipids à Smaller Lipids (Mechanical)
*Food still called Bolus*
The Stomach• Main reason we don’t need to eat
constantly
> Holds about 2 liters of food and water
• Some chemical digestion in the stomach
> Secretes Gastric Juice
![Page 12: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/12.jpg)
The Stomach: Gastric Juice• Gastric Juice:
> Mucus
> Lines stomach for protection and lubrication
> HCL
> Reacts with pepsinogen to turn it into pepsin
> Pepsinogen
> Turns to pepsin
The Stomach: Pepsin• Pepsin:
> Active form of pepsinogen
> Breaks polypeptides into smaller polypeptides
To Recap:• Food enters stomach
> Gastrin Stimulates release of Gastric Juice
> Gastric Juice contains mucus, HCL, Pepsinogen
– HCL and Pepsinogen react to produce Pepsin
« Pepsin breaks proteins into smaller polypeptides
« Food exits after 2‐6 hours called chyme
![Page 13: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/13.jpg)
The Stomach• With an average pH of 1.5‐3.5 how does the stomach survive?
> Not eaten from the inside out by the acid?
The Stomach: Protection• The cells of the stomach are made to
deal with the acid...with the aid of mucus.
> Mucous Cells: protection
> Parietal Cells: Secrete HCl
> Chief Cells: Secrete Pepsinogen
*All cells in stomach replaced about every 3 days*
You do not need to know the cells in red. Just thought the information would be helpful in understanding.
The Stomach: Where it goes next
• The chyme travels through a sphincter to the small intestine
![Page 14: Digestive System - Grosse Pointe Public Schools · >The digestive system increases the surface area or workable area –The larger the workable area the faster the digestion and absorption](https://reader033.vdocuments.us/reader033/viewer/2022043019/5f3bbffbdd474f2b4431ea1f/html5/thumbnails/14.jpg)
Stomach: Beginning à End
• Disacharides à Disacharides (Chemical)
• Small Polypeptides à VERY Small Polypeptides (Chemical)
• Small Nucleic Acids àSmaller Nucleic Acids (Mechanical)
• Small Lipids à Smaller Lipids (Mechanical)
**Food to Small Intestine‐Now called Chyme**
`