topic 2 - organisation Flashcards
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.
What is bile’s role in digestion?
Bile neutralises hydrochloric acid and emulsifies large drops of fat into smaller ones.
What is the structure of the heart?
The heart has muscular walls, a thicker left ventricle, 4 chambers, and valves to prevent backflow.
What is the primary function of the heart?
The heart pumps blood around the body in a double circulatory system.
What causes blood to flow into the right atrium?
Blood flows into the right atrium through the vena cava.
What is the function of coronary arteries?
Coronary arteries provide oxygenated blood to the heart.
What is the composition of blood?
Blood is composed of plasma, red blood cells, white blood cells, and platelets.
What function do platelets serve in the blood?
Platelets help the blood clot at the site of a wound.
Describe coronary heart disease.
Coronary heart disease occurs when the coronary arteries become blocked with fatty material, reducing blood and oxygen supply to the heart.
What is the purpose of stents in treating coronary heart disease?
Stents are inserted into arteries to keep them open and allow blood to flow through.
What are statins?
Statins are drugs that decrease levels of LDL bad cholesterol and increase levels of HDL good cholesterol.
What is the purpose of replacing faulty heart valves?
Faulty heart valves that do not open or leak need to be replaced to ensure the heart works efficiently.
What is heart failure and how can it be treated?
Heart failure can be treated with a heart transplant or by using an artificial heart while waiting for a donor.
What is the purpose of artificial blood?
Artificial blood is a salt solution that can keep people alive even if they lose 2/3 of their red blood cells, giving patients more time to produce new blood cells.
How long can artificial blood be used?
Artificial blood can only be used for short periods of time; then a blood transfusion has to take place.
What is the definition of health as per the text?
Health is a state of physical, mental, and social well-being, not merely the absence of disease.
What are the factors that can cause ill health?
Factors that can cause ill health include diet, stress, and life situations.
What are communicable diseases? Give an example.
Communicable diseases are infectious diseases caused by pathogens such as bacteria, viruses, and fungi, passed from one person to another. An example is the flu.
What are non-communicable diseases? Give an example.
Non-communicable diseases are diseases not passed from person to person. An example is heart disease.
How can diseases interact with each other?
Diseases can interact through one causing another or making its effects worse.
Why are individuals with a poor immune system more likely to suffer from communicable diseases?
If the immune system of an individual is poor, then they are more likely to become infected with a communicable disease as the body is less able to fight off any pathogens.
What can infections by viruses in certain parts of the body trigger?
Infections by viruses in certain parts of the body can trigger the growth of cancers.
How can the reduction in physical health affect mental health?
Reduction in physical health can prevent an individual from carrying out many tasks and/or reduce their life expectancy, potentially leading to mental illness such as depression.
What are some dietary factors affecting health?
Eating too little or too much food, not enough nutrients, or the wrong type of food can prevent a good, balanced diet, leading to issues like type 2 diabetes or obesity.
What is the relationship between stress and health?
Physical and mental stress can place strains on our bodies, potentially leading to problems such as heart disease, cancers, and mental illnesses.
What factors related to life situations can affect health?
Factors such as where you live, financial status, ethnic group, access to medical care, and levels of hygiene in your area can affect physical and mental health.
What kinds of diagrams can be used to display disease incidence information?
Disease incidence information can be displayed on frequency tables, bar charts, histograms, and scatter diagrams.
What are non-communicable diseases, and what are their risk factors?
Non-communicable diseases are not infectious, and risk factors include aspects of a person’s lifestyle and substances in the person’s body.
What is causation correlation in scientific studies?
To prove causation correlation, scientists need to find a causal mechanism, which is an explanation of how one factor influences another.
What dietary component can result in cardiovascular disease?
A diet containing lots of LDL (bad cholesterol) can lead to arteries becoming blocked, which increases blood pressure.
How does smoking affect cardiovascular health?
Smoking damages the walls of arteries, contributing to cardiovascular disease.
How can exercise influence heart health?
Exercise lowers blood pressure, reducing strain on the heart.
What is Type 2 diabetes associated with?
Type 2 diabetes is associated with obesity, which affects the body’s metabolism and fat molecule release into the blood.
How does alcohol affect liver and brain function?
Alcohol causes fatty liver, which can lead to liver failure, and it can damage nerve cells in the brain.
What lifestyle factors are linked to cancer?
Lifestyle risk factors for cancer include smoking (leading to various cancers), obesity (linked to bowel, liver, and kidney cancers), and UV light (linked to skin cancer).
What is cancer fundamentally caused by?
Cancer results from changes in cells that lead to uncontrollable growth and division, forming a tumor.
What are the two types of tumors mentioned?
Tumors can be benign (not cancerous, contained, and can be dangerous if they cause pressure or damage) or malignant (cancerous, can spread to other tissues and form secondary tumors).
What are some genetic risk factors for cancer?
Certain genes can be inherited that increase the likelihood of developing cancer.
What role do epidermal tissues play in plants?
Epidermal tissue covers the whole plant and is covered with a waxy cuticle that helps reduce water loss by evaporation.
What is the function of palisade mesophyll?
Palisade mesophyll tissue is found beneath the epidermal tissue and contains many chloroplasts for photosynthesis.
What is the function of xylem?
Xylem transports water and mineral ions from the roots to the stem and leaves, contributing to the transpiration stream.
How does phloem function in plants?
Phloem is responsible for transporting food substances in both directions, from leaves for use or from underground storage to parts of the plant that need it.
What process is known as translocation in plants?
Translocation is the movement of food substances made in the leaves up or down the phloem.
What are guard cells and their function?
Guard cells surround the stomata and control their opening and closing based on water availability, playing a crucial role in gas exchange.
How does temperature affect transpiration?
An increase in temperature causes molecules to move faster, resulting in a faster evaporation rate and increased transpiration.
What effect does high humidity have on transpiration?
High relative humidity decreases the concentration gradient between water vapor inside and outside the leaf, resulting in a slower rate of transpiration.
What is a potometer used for?
A potometer is used to measure the uptake of water by a plant, indicating the rate of transpiration.
How do guard cells respond to available water?
When lots of water is available, guard cells fill and change shape to open stomata, allowing more gases to exchange and more water to evaporate.
Where are most stomata located on a leaf and why?
More stomata are found on the bottom of the leaf to allow for gas exchange while minimizing water loss, as the lower surface is shaded and cooler.
How does air movement affect transpiration rates?
Increased air movement can lower the concentration of water vapor surrounding the leaf, leading to a steeper concentration gradient and faster diffusion, which increases transpiration rates.
What effect does light intensity have on transpiration?
Increased light intensity leads to higher rates of photosynthesis and more open stomata, resulting in increased evaporation and higher transpiration rates.
