Topic 2- Animal Tissues, Organs and systems Flashcards
What is the main function of the digestive system?
To digest food and absorb the nutrients obtained from digestion
What is the role of the pancreas and the salivary gland in the digestive system?
They are glands which produce digestive juices containing enzymes
What is the role of the stomach in the digestive system
Produces hydrochloric acid- which kills any bacteria present and provided the optimum acidic pH for the protease enzyme to function
What is the role of the small intestine in the digestive system?
The small intestine is the site where soluble food molecules are absorbed into the bloodstream
What is the role of the liver in the digestive system?
Produce bile (stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently
What is the role of the large intestine in the digestive system?
Absorbs water from undigested food producing faeces
What is the role of enzyme in the digestive system?
enzymes act as biological catalyst which speed up the rate of biological reactions (the breakdown of food) without being used up
How does the shape of an enzyme affect its function
Enzymes have a specific active site which is complementary to their substrate
What is metabolism
The sum of all the reactions in a cell or an organism
What type of metabolic reactions do enzymes catalyse?
Building larger molecules from smaller molecules (glucose to starch)
Changing on molecule to another (glucose to fructose)
breaking down larger molecules into smaller molecules (carbohydrate to glucose)
What is the lock and key hypothesis of enzyme function
The shape of the enzyme active site and the substrate are complementary, so can bind together to form an enzyme-substrate complex
How does temperature affect enzyme action?
Up to a certain point, increasing temperature increases enzyme action, as molecules have a higher kinetic energy. Above a certain temperature, the shape of the active site is altered and the enzyme becomes denatured, so it can no longer catalyse the reaction. The optimum temperature is around 37 degrees Celsius
How does pH affect enzyme function?
The optimum pH for most enzymes is 7 (apart of protease in the stomach). If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work
Where are amylase, protease and lipases produced in the body
Carbohydrases- amylase - salivary gland and pancreas; Maltese- small intestine
proteases: pepsin- stomach; others-pancreas and small intestine
Lipases: pancreas and small intestine
What is the role of amylase in the digestive system
Amylase breaks down starch into maltose and maltase break down maltose into glucose
What is the role of protease in the digestive system?
proteases break down proteins into amino acids,
What is the role of lipases in the digestive system?
lipases break down lipids into fatty acids and glycerol
How are the products of digestion used?
They are used to build bigger molecules.
Glucose is used as a substrate in respiration
Where is bile made and stored in the body
Bile is made by the liver and stored in the gallbladder
What is the role of bile in the digestive system?
Bile is an alkaline substance which neutralises the hydrochloric acid secreted by the stomach
Bile emulsifies lipids to form droplets- this increases the surface area for the lipases enzyme to work on
What is the heart?
An organ that pumps blood around the body
What is the purpose of the circulatory system
carries oxygen and other useful substances to bodily tissues, and removes waste substances
How does the double circulatory system work?
One pathway carries blood from the heart to the lungs- where the gaseous exchange of oxygen and carbon dioxide
one pathway carried the blood from the heart to the tissues
Where does blood pumped by the right ventricle go?
the lungs by the pulmonary artery
Where does the blood pumped from the right ventricle
Body tissues
Why is the double circulatory system important?
it makes the circulatory system more efficient- for example oxygenated blood can be pumped around the body at a higher pressure by the left ventricle
How many chambers does the heart have and what are they called
4-right atrium, right ventricle , left atrium, left ventricle
Why is the wall of the left ventricle thicker?
The left ventricle has to pump blood at a higher pressure around the whole body
What are the four main blood vessels associated with the heart?
Aorta (left): carries oxygenated blood from the heart to the body
Pulmonary vein (left): carries oxygenated blood from the lungs to the heart
Vena cava (right): carries deoxygenated blood from the body to the heart
Pulmonary artery (right)- carries deoxygenated blood from the hear to the lungs
What is the purpose of valves in the heart?
prevent the back flow of blood
What is the purpose of coronary arteries?
Coronary arteries supply the heart muscle with oxygenated blood
Describe the process of blood flow through the heart
Blood enters the right atrium via the vena cava and the left atrium via the pulmonary vein
The atria contract , forcing blood into the ventricles and causing valves to shut
After the ventricles contract, blood in the right ventricle enters the pulmonary artery (to the lungs) and blood in the left ventricle enters the aorta (to the body)
What is the approximate value of the natural resting heart rate?
70 beats per minute
How is the heart rate controlled?
Heart rate is controlled by a group of cells in the right atrium which act as a pacemaker. They release waves of electrical activity which cause the heart muscle to contract