topic 2 - organisation Flashcards
(74 cards)
What is the basic unit that makes up all living things?
Cells make up all living things.
Define a tissue.
A tissue is a group of specialised cells with a similar structure and function.
What is an example of muscular tissue?
Muscle tissue.
How is an organ defined?
An organ is formed from a number of different tissues, working together to produce a specific function.
What role does the stomach play in the digestive system?
The stomach is part of the digestive system, which has organs such as the liver and small intestine.
What are the glands associated with the digestive system?
Salivary glands and the pancreas, which produce digestive juices containing enzymes that break down food.
What does the stomach produce to aid digestion?
The stomach produces hydrochloric acid to kill bacteria and to provide the optimum pH for the protease enzyme to work.
What is the role of the small intestine?
The small intestine is where soluble molecules are absorbed into the blood.
What function does the liver serve in digestion?
The liver produces bile which is stored in the gall bladder and helps with the digestion of lipids.
What happens in the large intestine?
The large intestine absorbs water from undigested food to produce faeces, which passes out of the body through the rectum and anus.
What are enzymes?
Enzymes are biological catalysts that increase the rate of reaction without being used up.
What is the Lock and Key Hypothesis?
The Lock and Key Hypothesis is a simplified explanation of how enzymes work, where the shape of the substrate is complementary to the shape of the active site.
What temperature is considered optimal for enzyme activity?
The optimum temperature for most enzymes is around 37 degrees Celsius, which is body temperature.
What happens to enzymes at temperatures above their optimum?
At temperatures above the optimum, the rate of reaction rapidly decreases, and the enzyme may become denatured.
What does it mean when an enzyme is denatured?
When an enzyme is denatured, it means that the shape of the active site has changed so that the substrate can no longer fit.
What is the optimum pH of most enzymes?
The optimum pH for most enzymes is 7, but some enzymes produced in acidic conditions, like in the stomach, have a lower optimum pH.
What are carbohydrases and their function?
Carbohydrases convert carbohydrates into simple sugars, with amylase being an example that breaks down starch into maltose.
Where is amylase produced?
Amylase is produced in the salivary glands, pancreas, and small intestine.
What is the role of proteases?
Proteases convert proteins into amino acids, with pepsin being an example produced in the stomach.
What do lipases do?
Lipases convert lipids into fatty acids and glycerol, produced in the pancreas and small intestine.
What is Benedict’s test used for?
Benedict’s test is used for sugars and turns brick red if sugars are present.
What does the iodine test indicate?
The iodine test indicates starch and turns blue-black if starch is present.
What is tested for using the Biuret test?
The Biuret test is used for proteins and turns purple if proteins are present.
How does the emulsion test for lipids work?
The emulsion test involves adding ethanol and results in a cloudy layer if a lipid is present.