Wednesday the 13th

Today in 2nd period biology we discussed the Kidney. Some of the notes for today are the following...

The kidney

- Removes metabolic waste and helps to maintain homeostasis (i.e. keeps salt and water levels in balance)

- Three major steps the kidneys preform are...

- Filtering blood

- Reabsorbing nutrients

- Collection and excretion

- The nephron

-Basic unit of the kidney

- Filtration

- water, Urea, glucose, salts, amino acids and vitamins filter into nephron

- Reabsorption

- needed materials reenter the blood stream

- Collection and

- concentrated urine is collected and leaves the kidney

The second half of class we saw a urine demonstration were we tested for glucose.

There is no homework due tomorrow but there is a test friday on digestion and excretion. The homework that was due today was the kidney dissection lab on pages 23-28 in the unit packet.

IZZY IS OUR NEXT SCRIBE

This morning we took out our Enzymes and Digestive Fluids Summary sheet for a stamp. We went over it in class, going over the specific enzymes and digestive fluids. This was important because we do have a quiz for tomorrow on Digestion.

Therefore, to prepare, Mrs. Stein came up with 3 questions on the board to quiz ourselves.

1. asked to describe carbohydrate digestion, where it takes place, what enzymes are involved and what molecules it acts on.

As a class, we decided that carbohydrate digestion begins in the mouth where amylase breaks down starch to maltose. Once the food leaves the stomach, pancreatic juice causes more amylase to finish changing starch into maltase, acting in the duodenum. The maltase digests the maltose, breaking it up into glucose molecules.

Starch --> Maltose  --> Glucose
       amylase             maltase

2. -Pepsin breaks down proteins into smaller polypeptide chains, found in the stomach. HCl kills the bacteria and lowers the pH level.
3. -Bile salts break big fat molecules into smaller ones in significance of a larger surface area. This is known as Emulsification.
After our discussion, we went to our lab benches and resumed with our Nutrient Lab. Today, we finished Benedict's solution, and observed the clear and orange outcomes in the test tubes. We will be finishing the rest of our lab tomorrow.



Homework!:

-Study for the digestion quiz tomorrow!

-Nutrient Lab due by end of class tomorrow.

The Digestive System

Today was a pretty average day in biology.

1. First we handed in our flow map which was homework


2. Then we took notes on the organs of digestion


3. After we introduced the emzyme and nutrient lab

Homework:

• Nutrient Pre-Lab due tomorrow


• Read 30.2 fir tomorrow


• Enzyme reading chart due thursday


• Visit Me Extra Credit by Tuesday next week

Here are the notes in case anyone missed them, the next scribe is Dana!

Digestion:

• 
  
  breaks down large molecules into smaller molecules which can be used by cells


• 
  
  Physical & chemical, alimentary canal- one way tube which food passes through body


• 
  
  Acessory structures: dont carry food but aid in digestion

Mouth:

• 
  
  Mechanical digestion- teeth crush food


• 
  
  saliva moistens food and contains salivary amylase: turns starch into simpler sugars

Esophagus:

• 
  
  Muscular- connects pharynx & stomach Perisatlisis-waves of muscle contractions


• 
  
  bolus enters the stomach thru a sphincter, acid may back up into the esophagus

Stomach:

• 
  
  Muscular sac lined w/ mucus ~ protection & lubrication


• 
  
  mechanical digestion & chemical digestion


• HCI kills bacteria lowers pH to activate pepsin


• 
  
  Peptic ulcer- hole in stomach wall: caused by bacteria

Small Intestine:

• 
  
  Duodenum- 1st part of the small intestine, enzymes & fluids enter here


• 
  
  Carbs, lipids, & proteins digested here, nutrients absorbed


• 
  
  lined w/ finger like projections called villi- increase surface area for absorption


• water, cellulose, & indegestibles remain

Acessory Structures:

• 
  
  Liner produces bile which emulsifies fat, gallbladder stores bile, & oancreas produces enzymes Large Intestine:


• 
  
  absorbs water from undigested material & bacteria synthesize vitamin K

Welcome Back!

Monday, April 4th Schedule: 1.Talk about grades, science contest, seats, labgroups, and blog. 2.Discuss new unit. -What do you already know? 3.Begin homework. Homework: 1.Read 30.3 with flow map. 2. Visit Mrs. Stein for homework pass by tuesday. 3. Extra credit: science contest. Basically today in class we got back into the regular routine after break. We got our new packets and calanders. In this unit we will be learning about digestion and excreation. Mrs. Stein also told us we would be disecting things in the near future, which i personally was not so thrilled about. She also passed out our grade reports and discussed the extra credit opportunity. Durring the last ten minutes of class we got to start our flow maps. The next scribe will be... Gabby!