Chapter 3 Flashcards Preview

Maciej Biology Maciej > Chapter 3 > Flashcards

Flashcards in Chapter 3 Deck (22):

What is a tissue ?

A group of cells working together to preform a specific function


What is an organ ?

A group of tissue's that work together to preform a specific function


What is an organ system ?

A group of organs working together to preform a specific function


What does the mouth do in digestion ?

-Physical digestion by teeth
-Chemical digestion by saliva


How does the stomach aid digestion

-Digestion by stomach acid and digestive enzymes


How does the liver aid digestion ?

-Produces bile which emulsifies fat (breaks them down into smaller pieces) and neutralises stomach acid


How does the pancreas aid digestion ?

Sits below stomach:
-Creates digestive enzymes to help break down food


How does the small intestine aid digestion ?

Food moves here after the stomach:
-Digested food is absorbed from small intestine into the blood stream
-Enzymes produced to break down food


How does the Large intestine aid Digestion ?

-Water is re-absorbed into the bloodstream and the rest is passed onto the rectum where the left over is excreted from the anus


What is the chemical formula for glucose ?



How do you test for Carbohydrates ?

Iodine test for starch:
-yellow/red iodine turns blue if starch is present
Benedict's test for sugars:
-Blue solution turns red on heating if starch is present


How do you test for Protein ?

Biuret test:
-Biuret reagent turns purple if protein is present


How do you test for lipids ?

Ethanol test:
-Ethanol gives a solution containing lipids a cloudy white layer


What are proteins ?

Molecules used for growth and repairing muscle tissue:
-Made up of long chains of amino acids


What are Carbohydrates ?

Main source of energy for humans:
-Made up of simple sugars such as glucose and sucrose


what are Lipids ?

Fats and oils used as energy stores in our body:
-Made up of 3 molecules of fatty acids joined to 1 molecule of glycerol


What are enzymes and how do they work?

Proteins made up of amino acids:
-Biological catalysts
-Work by lock and key theory
--substrate locks into the enzymes active site
--substrate splits into 2 products making it easier and quicker to digest
--enzyme can be used again


What is metabolism ?

The sum of all reactions in your body


What and how does it affect the effect of enzymes on a reaction ?

-Greater temperature the greater the kinetic energy the faster the reaction
-If temperature is too great the chains of amino acids begin to unravel and the enzyme becomes denatured
-A change in pH can stop the forces holding an active site in place meaning that the enzyme stops working completely


Which enzyme breaks down:
-Fatty Acids/lipids



Describe lock and key theory

-Substrate fits into the active site of the enzyme
-Substrate splits into products, making them quicker to digest
-Products leave the active site and the enzyme can be used again


What is bile ?

Bile is produced in the liver and stored in the gall bladder, it i s an alkaline that neutralises the stomach acid and emulsifies fat to form small droplet that increase the surface area to volume ratio