B2 Flashcards
(93 cards)
What is the definition of a cell?
Basic building blocks of all living organisms
What is a tissue?
A group of cells with similar structures and functions
What is an organ?
Groups of tissues performing specific functions
What are organ systems?
Organs organised into organ systems to work together to form organisms
What is an enzyme?
Proteins that act as a biological catalyst
How do digestive enzymes work?
They convert food into small soluble molecules that can be absorbed into bloodstream
What enzyme breaks down carbohydrates?
Carbohydrates (amylase) break down carbohydrates into simple sugars
What enzyme breaks down proteins?
Protease break down protein into amino acids
What enzyme breaks down lipids?
Lipase breaks down lipids into glycerol and fatty acids
What is the function of bile?
Bike (which is made in the liver) neutralises hydrochloric acid from the stomach
What is the heart?
An organ that pumps blood around the body in a double circulatory system
Why is it called a double circulatory system?
The right ventricle pumps blood to the lungs where gas exchange takes place. The left ventricle pumps blood around the rest of the body
What is heart rate controlled by?
The natural resting heart rate is controlled by a group of cells located in the right atrium that act as a pacemaker.
What are the four chambers of the heart?
Right atrium, right ventricle, left atrium, left ventricle
How does blood travel through the heart?
Blood flows into atria in heart from pulmonary vein and vena cava.
Atria contract and push blood into ventricles.
Ventricles contract, blood is forced into pulmonary artery and aorta, out of the heart
What is a catalyst?
A substance which increases the speed of a reaction without being changed or used up
What are the characteristics of an enzyme?
They all have an active site that is complimentary to its substrates
What happens to enzyme activity if temperature is too high?
The enzymes active site will change shape and the enzyme will become denatured
What is meant by an optimum pH level?
The pH level at which the enzyme works best at
What is the food test for sugars?
Benedict’s solution added to a food sample, warm in a water bath, if positive colour change from blue to brick red
What is the food test for starch?
Add iodine solution to food sample, if positive colour change from orange to blue black
What is the food test for proteins?
Add biuret solution to food sample, if positive colour change from blue to purple
What is the food test for lipids?
Add ethanol to food sample, shake, white emulsion appear if a positive test