Cellular Respiration
What is the main purpose of cellular respiration?
To release energy from glucose.
What is the main job of the digestive system?
To break food down and absorb nutrients.
What gas do we breathe in that is needed for respiration?
Oxygen
What is the main job of the cardiovascular system?
To transport nutrients (e.g. O2, glucose, minerals) around the body and remove waste (e.g. CO2).
What does the M in MRS GREN stand for?
Movement
What two substances are needed for aerobic respiration?
Glucose and oxygen.
Where does digestion begin?
The mouth.
What is the name of the tiny air sacs where gas exchange occurs?
Alveoli.
What organ pumps blood around the body?
The heart.
What does the first R in MRS GREN stand for?
Respiration.
Write the word equation for aerobic respiration.
Glucose + oxygen → carbon dioxide + water + energy.
What is the main function of the small intestine?
To absorb digested nutrients into the bloodstream.
How does oxygen move from the alveoli into the blood?
Oxygen diffuses through the thin walls of the alveoli into nearby blood capillaries.
What is the difference between arteries and veins?
Arteries carry blood away from the heart; veins carry blood towards the heart.
What does the S in MRS GREN stand for, and why is it important for living things?
Sensitivity — the ability to detect and respond to changes in the environment.
Why do muscle cells need more oxygen and glucose during exercise?
Muscles are doing more work, so they need more energy. They therefore need more glucose and oxygen for cellular respiration.
Why are the small intestine and its villi well suited for absorbing nutrients?
The small intestine is long and has many villi, giving it a large surface area for nutrient absorption. The villi have a good blood supply to carry nutrients away.
Why does exercise cause your breathing rate to increase?
Working muscles need more energy, so they need more oxygen for cellular respiration. Breathing increases to bring more oxygen into the body and remove more carbon dioxide
Explain how the heart, lungs and blood work together to deliver oxygen to muscle cells.
The lungs add oxygen to the blood and remove carbon dioxide. The heart pumps the oxygenated blood around the body, delivering oxygen to cells.
Choose two parts of MRS GREN and explain how they are connected.
E.g. Nutrition and respiration are connected because organisms obtain nutrients such as glucose, which can be used in cellular respiration to release energy.
A student starts running and their muscles need more energy. Explain how the respiratory and cardiovascular systems work together to increase cellular respiration.
Exercise increases the muscles' energy demand → breathing increases to bring in more oxygen → heart rate increases to transport oxygen and glucose to muscles → muscles carry out more cellular respiration → more energy is released.
Explain how food travels through the digestive system from the mouth to the small intestine, including what happens to the food along the way.
Mouth → oesophagus → stomach → small intestine. Food is mechanically broken down in the mouth, mixed with digestive juices in the stomach, and further digested in the small intestine, where nutrients are absorbed.
Explain how oxygen gets from the air outside your body to a muscle cell where it is used in cellular respiration.
Air enters through the nose/mouth → trachea → bronchi → bronchioles → alveoli → oxygen diffuses into the blood → blood carries it to the heart → heart pumps it to muscles → oxygen diffuses into muscle cells.
Explain the pathway of a red blood cell from the heart to a muscle cell and back to the heart.
Heart → artery → smaller blood vessels/capillaries → muscle cell → veins → heart. At the muscle, oxygen leaves the blood and enters the muscle cell, while carbon dioxide enters the blood.
Explain how MRS GREN is used to identify living things, and compare this with how mātauranga Māori / te ao Māori understands and views living things.
MRS GREN classifies living things by looking for seven life processes of the acronym.
Mātauranga Māori / te ao Māori views living things as possessing mauri "life force", connected to each other, people, the environment and whenua, rather than simply classifying them by observable or measurable life processes.