Topic 3B – More Exchange and Transport Systems Flashcards
What is the function of digestive enzymes?
Digestive enzymes break down large molecules (e.g., carbohydrates, proteins, fats) into smaller molecules that can be absorbed by the body.
What are the main digestive enzymes and their functions?
~Amylase: Breaks down starch into maltose (in saliva and pancreatic juice).
~Protease: Breaks down proteins into amino acids (e.g., pepsin in the stomach).
~Lipase: Breaks down lipids into fatty acids and glycerol (in the small intestine).
What is absorption in the context of digestion?
Absorption is the process by which nutrients from digested food pass through the walls of the small intestine into the bloodstream or lymphatic system.
What structures in the small intestine aid absorption?
The small intestine has villi and microvilli, which increase surface area for nutrient absorption.
What is the function of haemoglobin?
Haemoglobin is a protein in red blood cells that binds to oxygen, transporting it from the lungs to tissues and organs.
How does haemoglobin bind to oxygen?
Haemoglobin binds to oxygen through cooperative binding, where the binding of one oxygen molecule makes it easier for additional oxygen molecules to bind.
What is the oxygen dissociation curve for haemoglobin?
The oxygen dissociation curve shows the relationship between the partial pressure of oxygen and the percentage of haemoglobin saturated with oxygen.
How does carbon dioxide affect haemoglobin’s ability to bind oxygen?
Increased carbon dioxide levels lower blood pH, causing haemoglobin to release oxygen more readily, a phenomenon known as the Bohr effect.
What is the function of the circulatory system?
The circulatory system transports gases, nutrients, hormones, and waste products throughout the body.
What are the main components of the circulatory system?
The main components are the heart, blood vessels (arteries, veins, capillaries), and blood.
What is the difference between open and closed circulatory systems?
~Closed circulatory system: Blood is confined to vessels and circulates throughout the body (e.g., in humans).
~Open circulatory system: Blood is not contained in blood vessels and flows freely through body cavities (e.g., in insects).
What is the role of capillaries in the circulatory system?
Capillaries are small, thin blood vessels that allow for the exchange of gases, nutrients, and waste products between the blood and tissues.
What is the function of the heart?
The heart pumps blood throughout the body, maintaining blood circulation and supplying tissues with oxygen and nutrients.
How is the heart structured to carry out its function?
The heart has four chambers (two atria and two ventricles), with valves to ensure one-way blood flow and prevent backflow.
What are the two main circuits in the circulatory system?
~Pulmonary circuit: Carries deoxygenated blood from the heart to the lungs and back.
~Systemic circuit: Carries oxygenated blood from the heart to the rest of the body and back.
What is the role of the coronary arteries?
The coronary arteries supply oxygenated blood to the heart muscle itself.
What is atherosclerosis?
Atherosclerosis is the buildup of fatty deposits (plaques) in the walls of arteries, leading to narrowed and less flexible arteries.
How can atherosclerosis lead to heart disease?
Atherosclerosis can restrict blood flow, increasing the risk of heart attack, stroke, or other cardiovascular diseases.
What is hypertension?
Hypertension, or high blood pressure, is a condition where the force of blood against the walls of arteries is consistently too high.
How does hypertension increase the risk of cardiovascular disease?
Hypertension can damage blood vessels and the heart, increasing the risk of atherosclerosis, heart attack, and stroke.
What are the lifestyle factors that increase the risk of cardiovascular disease?
Poor diet, lack of exercise, smoking, excessive alcohol consumption, and high stress levels can all increase the risk of cardiovascular disease.
What is the function of xylem in plants?
Xylem transports water and dissolved minerals from the roots to the rest of the plant.
How does water transport occur in the xylem?
Water moves through xylem vessels by capillary action, transpiration pull, and root pressure.
What are the main structural features of xylem vessels?
Xylem vessels are made of long, hollow tubes with thick, lignified walls that provide structural support and prevent collapse.
What is the function of phloem in plants?
Phloem transports organic nutrients, particularly sugars, from the leaves to other parts of the plant.
What is translocation in plants?
Translocation is the movement of sugars and other organic substances in phloem from sources (e.g., leaves) to sinks (e.g., roots, fruits).
What is the process of active transport in phloem loading?
Active transport uses energy to move sugars into the phloem from surrounding cells, creating a high concentration of sugars that drives water movement into the phloem by osmosis.
What are the structural features of phloem vessels?
Phloem consists of sieve tubes, companion cells, and phloem fibers that help in the transport of nutrients and structural support.
What is Digestion?
The breakdown of food into smaller molecules (nutrients) that can be absorbed by the body.
What is Absorption?
The process by which nutrients from digested food pass through the walls of the small intestine into the bloodstream.
What is Haemoglobin?
A protein in red blood cells that binds to oxygen for transport throughout the body.
What is the Oxygen dissociation curve?
A graph showing the relationship between the oxygen partial pressure and the oxygen saturation of haemoglobin.
What is the Circulatory system?
A system of blood vessels and the heart responsible for transporting substances around the body.
What are Capillaries?
Tiny blood vessels where the exchange of gases, nutrients, and waste occurs between the blood and tissues.
What is Atherosclerosis?
The buildup of fatty deposits (plaques) inside arteries, which can lead to narrowing and blockages.
What is Hypertension?
A condition of high blood pressure that puts strain on the heart and blood vessels.
What is Xylem?
Vascular tissue in plants that conducts water and dissolved minerals from the roots to the rest of the plant.
What is Phloem?
Vascular tissue in plants that transports organic nutrients, particularly sugars, from the leaves to other parts of the plant.
What is Translocation?
The process by which sugars and other organic compounds are transported through the phloem in plants.
What is Transpiration pull?
The process by which water is pulled up through the plant by evaporation from the leaves, creating a negative pressure in the xylem.
