Nimisha Jain

 

The Homeostasis Workshop

a. Define homeostasis

The maintenance of a relatively stable internal environment regardless of the external environment. It works by negative feedback to maintain conditions within a range.

 

b. What is the purpose of insulin?

Unlocks channel proteins- insulin monomers attach to insulin receptors on the surface of cell membranes, which signal glucose transport channels to come to the membrane. The glucose transport channels allow glucose to pass into the cell. Some of the glucose is then absorbed by the liver and stored as glycogen as a reserve energy supply. Some glucose is absorbed by body cells such as muscle to be used during the process of cellular respiration (produces energy). Insulin production decreases as the blood glucose level returns to normal.

 

c. What is meant by negative feedback?

When something goes wrong internally in the body, signals are sent so the body realizes what happens so the body can fix the problem and maintain homeostasis.

 

d. How do the different systems work together to regulate blood sugar?

Here is an example: The pancreas regulates the blood sugar levels, so when it realizes blood sugar levels are low, it releases glycogen, which travels to the liver, it is then broken down into glucose, which is then released in the circulatory system.

 

The Transport Workshop

a. What is active transport?

The pumping of molecules against their concentration gradient with the use of ATP (energy).

 

b. What is an ion pump?

Also called electrogenetic pumps, are special proteins which actively transport ions resulting in a ionic and voltage gradient. This gradient is a form of stored energy used to fuel other processes. The protein acts as a pump using ATP to transport ions against their concentration gradient.

 

c. What is cotransport?

Coupled massage of two materials across a membrane.

Example:

• Sucrose cannot get into the cell by itself.

• Hydrogen is pumped out of the cell against its concentration gradient.

• Once it is outside its cell, its starts to move down the concentration gradient.

• As hydrogen reenters the cell, it “opens a door” for sucrose to enter the cell.

 

d. What is endocytosis? Phagocytosis? Pinocytosis?

Endocytosis is the importing of materials to the cell by infolding of plasma membrane.

• Phagocytosis (Cell Eating)

• Pinocytosis( Cell Drinking)

 

e. Infer:  what is exocytosis?

The exporting of materials out of the cell through the outfolding of the plasma membrane.

 

f. What is passive transport?

Movement of molecules across the cell without the use of energy.

 

g. Distinguish between simple diffusion, facilitated diffusion, and osmosis.

Simple Diffusion: Movement of molecules from areas of high concentration to an area of low concentration. Diffusion occurs along a concentration gradient, which refers to the relative density of one substance versus another.

Facilitated Diffusion: Passive transport of molecules using no energy with the aid of special proteins. The protein goes through a shape change so the molecule can pass through.

Osmosis: Diffusion of water. Hypertonic has more solute and less water. Hypotonic has less solute and more water. Water moves around until equilibrium is reached.

 

h. Why are transport mechanisms important to all living things?

Transport mechanisms allow the cell to maintain equilibrium (osmosis, if too much water got in the cell, our blood cells would explode, if too little water got in the cell, our cells would shrivel), so the cells can function properly. It also allows the cell to “eat and drink food.”

 

i. Why is homeostasis important to life?

It’s important for many reasons. An example would be regulating temperature, if our temperature wasn’t being regulated, our cells would not be able to function properly.

 

j. How can you use this information in your final product?

To understand external functions of the body, one must understand what is going on internally and these processes handle the basics of what is happening internally in our body, so to understand the more complex topics, we must first understand basic internal processes.

 

The Water Potential Workshop

No questions.