Term
| After a period of training, the heart rate is often decreased when at rest although the cardiac output is unchanged. Suggest an explanation for this. |
|
Definition
| Training builds up the heart muscle, so stroke volume is increased |
|
|
Term
| Complete the equation: Cardiac output = |
|
Definition
| heart rate x stroke volume |
|
|
Term
| Complete the equation: Pulmonary ventilation= |
|
Definition
| Tidal volume x breathing rate |
|
|
Term
| Describe in stages how Vibrio Cholerae causes dehydration and diarrhea after chloride ion channels in the epithelial cells are opened. |
|
Definition
• Chloride ions diffuse into the lumen
• Water potential in epithelial cells increases
• Water moves by osmosis from the epithelial cells to the lumen, causing watery diarrhoea
• Ions diffuse from surrounding tissues into epithelial cells
• Water moves by osmosis from surrounding tissues into epithelial cells, causing dehydration. |
|
|
Term
| Describe the method of cell fractionation. |
|
Definition
| Cell membrane is destroyed; contents emptied into a test tube; a centrifuge separates organelles based on size and density |
|
|
Term
| Describe the seven main steps of carbohydrate digestion. |
|
Definition
1. Food is broken down by chewing
2. Salivary amylase is mixed with food
3. Amylase hydrolyses starch to maltose - mineral salts in saliva maintain neutral pH
4. Food moves down oesophagus by peristalsis to stomach - acid denatures amylase
5. Food moves to small intestine and is mixed with pancreatic juice - hydrolysing remaining starch
6. Alkaline salts produced by intestinal wall and pancreas maintain neutral pH
7. Food pushes along small intestine - epithelial wall produces maltase, sucrase and lactase. |
|
|
Term
| Describe the structure of the Vibrio Cholerae bacterium. |
|
Definition
| Comma-shaped; has a single polar flagellum; some forms have a protective capsule |
|
|
Term
| Give four limitations of the SEM (scanning electron microscope). |
|
Definition
Living specimens cannot be observed in a vacuum.
A complex staining process is required.
The sample may be contaminated by artefacts.
It has a lower resolving power than the TEM. |
|
|
Term
| Give four limitations of the TEM (transmission electron microscope). |
|
Definition
Living specimens cannot be observed in a vacuum.
A complex staining process is required.
The specimen must be extremely thin.
The sample may be contaminated by artefacts. |
|
|
Term
| Give four risk factors, other than smoking, which are associated with emphysema. |
|
Definition
| Air pollution, chemicals, poisonous gases, asthma |
|
|
Term
| Give four steps to show what happens when we exhale. |
|
Definition
1. Diaphragm muscles relax and diaphragm pulls back up
2. External intercostal muscles relax and ribs move back down due to gravity
3. Volume inside thorax decreases, so pressure increases
4. Air moves down a concentration gradient out of the lungs until equilibrium. |
|
|
Term
| Give four steps to show what happens when we inhale. |
|
Definition
1. Diaphragm muscles contract and diaphragm flattens
2. External intercostal muscles contract, pulling ribcage up and out
3. Volume inside chest cavity (thorax) increases, so pressure decreases
4. Air moves down a pressure gradient into the lungs |
|
|
Term
| Give as many risk factors as possible associated with coronary heart disease. |
|
Definition
| Diet - excess of saturated fats, cholesterol, salt; smoking; high blood pressure; high blood cholesterol level; obesity; lack of physical activity; alcohol |
|
|
Term
| Give three biological functions of lipids. |
|
Definition
Any three of:
-energy storage
-cell membranes
-capturing light energy
-hormones and vitamins
-thermal insulation
-electrical insulation around nerves
-repels water from surfaces of skin, fur and feathers. |
|
|
Term
| Give three ways in which exercise can reduce the risk of CHD. |
|
Definition
| Prevents obesity; lowers blood pressure; increases fitness, building up heart muscles |
|
|
Term
| Give two advantages of oxygenated and deoxygenated blood being completely separate. |
|
Definition
1. Blood reaching body tissue is maximally oxygenated
2. Blood at the gas exchange surface is maximally deoxygenated, maintaining a concentration gradient for gas exchange |
|
|
Term
| Give two reasons why it is difficult to eradicate TB by vaccination. |
|
Definition
| Antigenic variability; many vaccinated people destroy the bacterium before memory cells are produced. |
|
|
Term
| How are phagocytes attracted to a site of infection? |
|
Definition
| Pathogens release chemoattractants |
|
|
Term
| How do oral rehydration solutions work? |
|
Definition
| They contain water, glucose and ions; glucose and ions are absorbed by diffusion from the intestine to the epithelial cells, creating a water potential gradient by which water can be absorbed by osmosis |
|
|
Term
| How does emphysema reduce the efficiency of gas exchange? |
|
Definition
|
|
Term
| How does fibrosis result in scar tissue? |
|
Definition
| Macrophages may accumulate in connective tissue between alveoli - eventually forming hard lumps |
|
|
Term
| How does inflammation occur? |
|
Definition
| Damaged cells release histamine - causes an increase in blood flow of the capillaries - platelets cause swelling and redness |
|
|
Term
| How does the immune system detect invading pathogens? |
|
Definition
| Invaded cell or phagocyte presents antigens of pathogens; these are recognized by the T-helper cells which receptor proteins complementary to the antigen |
|
|
Term
| In cell fractionation what are the three key conditions of the solution containing the sample and why? |
|
Definition
| Cold to reduce enzyme activity which could break down the organelles; isotonic to prevent organelles from bursting by osmosis; and buffered to maintain a constant pH, to prevent enzymes from denaturing. |
|
|
Term
| In practice, the theoretical resolving power of an electron microscope cannot always be achieved. Why not? |
|
Definition
| Due to human errors in the preparation of the sample |
|
|
Term
| In the cardiac cycle, what is the diastole? |
|
Definition
| The period during which the atria and ventricles are relaxed |
|
|
Term
| In what two ways can pathogens cause disease? |
|
Definition
| Damaging the host; producing toxins |
|
|
Term
| Name and describe a test for lipids and give the positive result. |
|
Definition
| Emulsion test; add sample to ethanol and shake; remove top layer and add remaining solution to water; positive result is a cloudy-white emulsion |
|
|
Term
| Name and describe a test for non-reducing sugars and give the positive result. |
|
Definition
| Negative result for Benedict's test; add hydrochloric acid and sodium hydrogencarbonate; repeat Benedict's test; positive result is a brick-red solution |
|
|
Term
| Name and describe a test for peptide bonds and give the positive result. |
|
Definition
| Biuret test; add equal volumes of sodium hydroxide and copper sulfate to the solution; positive result is a mauve-purple solution |
|
|
Term
| Name and describe a test for reducing sugars and give the positive result. |
|
Definition
| Benedict's test; heat sample with Benedict's reagent; positive result is a brick red solution. |
|
|
Term
| Name four natural defences of the body to pathogens. |
|
Definition
| Mucus layer; enzymes that break down pathogens; stomach acid; white blood cells |
|
|
Term
| Name four ways pathogens can enter the host body. |
|
Definition
| Cuts, bites; sexual transmission; gas exchange system; digestive system |
|
|
Term
| Name the two types of proteins used in facilitated diffusion. |
|
Definition
| Channel proteins and carrier proteins |
|
|
Term
| Name three things that happen during an asthma attack. |
|
Definition
Muscle around bronchi contracts;
Mast cells release histamine, causing inflammation of the airways;
Extra mucus is produced. |
|
|
Term
| Name two types of phagocytes. |
|
Definition
| Macrophages and neutrophils |
|
|
Term
| Name two ways in which bacteria can resist phagocytosis. |
|
Definition
producing chemicals which prevent WBCs from being attracted to the site
waxy cell wall makes digestion harder |
|
|
Term
| Simple diffusion across the plasma membrane is dependent on what two main properties? |
|
Definition
| Size and lipid solubility |
|
|
Term
| Suggest a reason why males are more likely to get CHD than females (other factors controlled). |
|
Definition
| Oestrogen can protect against CHD |
|
|
Term
| Suggest three ways in which drinking water can become contaminated by Vibrio Cholerae. |
|
Definition
· Drinking water is not properly purified
· Untreated sewage leaks into water systems
Organisms e.g. shellfish feed on untreated sewage |
|
|
Term
| Suggest three ways in which high blood pressure increases the risk of heart disease. |
|
Definition
| Greater chance of an aneurysm; heart must work harder so is more prone to failure; artery walls may thicken, restricting blood flow |
|
|
Term
| The nucleus has an inner and outer membrane. What is this double membrane called? |
|
Definition
|
|
Term
|
Definition
| Fatty deposits in the coronary arteries |
|
|
Term
|
Definition
| Toxins which are only released when the cell dies and the cell wall disintegrates. |
|
|
Term
|
Definition
| Toxins which are released from a bacterium as it grows. |
|
|
Term
|
Definition
| Proteins produced by virus-infected cells which trigger the production of an inhibitor of the virus' mRNA, preventing it from replicating |
|
|
Term
|
Definition
| Complex associations of lipids, proteins and cholesterol |
|
|
Term
| What are the three stages of the cardiac cycle? |
|
Definition
| Atrial systole, ventricular systole, diastole |
|
|
Term
| What are the two pathogens that cause TB? |
|
Definition
| Mycobacterium tuberculosis and Mycobacterium bovis |
|
|
Term
| What can cause a polypeptide to coil and form an alpha helix? |
|
Definition
| Hydrogen bonds between N-H and C=O groups. |
|
|
Term
| What causes a blood clot to form at the site of a plaque? |
|
Definition
| Endothelium breaks down, blood platelets stick to the damaged site and a blood clot forms |
|
|
Term
| What causes atheroma to arise in the coronary arteries? |
|
Definition
| Damage to endothelium attracts white blood cells which absorb cholesterol-containing LDLs. |
|
|
Term
| What collective name is given to diseases such as emphysema? Name another example of this type of disease. |
|
Definition
| Chronic Obstructive Pulmonary Diseases (COPDs); chronic bronchitis |
|
|
Term
| What distinguishes a phospholipid from a triglyceride? |
|
Definition
| A phosphate-containing compound in the place of a fatty acid. |
|
|
Term
| What distinguishes high-density lipoproteins from low-density lipoproteins? |
|
Definition
| HDLs have a higher proportion of protein |
|
|
Term
| What does Vibrio Cholerae do upon infection? |
|
Definition
| Surviving bacteria which reach the intestines produce a toxic protein which binds to chloride ion channels of epithelial cells, causing them to open |
|
|
Term
| What force causes organelles to separate in ultracentrifugation? |
|
Definition
|
|
Term
| What four properties of exchange surfaces make them easily colonised by pathogens? |
|
Definition
| Thin; moist and sticky; good blood supply; large surface area |
|
|
Term
| What four roles do activated T-cells have? |
|
Definition
Stimulating phagocytosis
Stimulating division of B cells by mitosis
Killing infected cells, either by producing perforin or by specializing to cytotoxic T-cells
Developing into memory cells for future infection |
|
|
Term
| What four things must a microorganism do to be considered a pathogen? |
|
Definition
gain entry to the host
colonise the tissue of the host
resist the defences of the host
cause damage to the host tissues |
|
|
Term
| What four types of bonds hold a protein's tertiary structure in place? |
|
Definition
| Disulfide bridges, hydrophobic interactions, van der Waals forces and ionic bonds. |
|
|
Term
| What happens after a T-helper cell binds to an antigen-presenting cell? |
|
Definition
| The T-helper cell is activated and divides rapidly by mitosis. |
|
|
Term
| What happens after the formation of a phagosome? |
|
Definition
| Phagosome fuses with a lysosome to form a phagolysosome which contains enzymes and toxic chemicals which digest the pathogen |
|
|
Term
| What happens during the diastole? |
|
Definition
| Blood enters the left atrium from the pulmonary vein and right atrium from the vena cava; pressure in atria increases; atrioventricular valve opens; blood flows from atria to ventricles |
|
|
Term
| What is a catabolic reaction? |
|
Definition
| A reaction which breaks larger molecules into smaller ones. |
|
|
Term
|
Definition
| A measure of the probability that damage to health will occur as a result of the hazard |
|
|
Term
| What is an anabolic reaction? |
|
Definition
| A reaction which links smaller molecules into larger ones. |
|
|
Term
|
Definition
| When the artery is weakened by damage to the artery wall and swells up due to blood pressure |
|
|
Term
|
Definition
| A substance, usually a protein, that is recognized as foreign by the immune system and therefore stimulates an immune |
|
|
Term
|
Definition
| When a pathogen gains entry into a host and colonises a tissue. |
|
|
Term
|
Definition
| The narrowing of the arteries due to atheroma |
|
|
Term
|
Definition
| Removing toxins from the body |
|
|
Term
| What is formed when the cell membrane of a phagocyte fuses around a bacterium? |
|
Definition
|
|
Term
| What is it called when the artery is weakened by damage to the artery wall and swells up due to blood pressure? |
|
Definition
|
|
Term
| What is myocardial infarction? |
|
Definition
| The medical term for a heart attack |
|
|
Term
| What is perforin and how does it kill infected cells? |
|
Definition
| A protein released by T-cells which perforates the plasma membrane, causing it to become freely permeable to all substances, so that the cell dies. |
|
|
Term
| What is plaque in the arteries? |
|
Definition
| The rough surface of atheroma |
|
|
Term
| What is the endothelium of an artery? |
|
Definition
| The layer of cells lining the inside of the artery |
|
|
Term
| What is the first step in humoral immunity? |
|
Definition
| The surface antigens of the invading pathogen are taken up by B cells |
|
|
Term
| What is the function of glycoproteins? |
|
Definition
| They enable the cell to be recognised by other cells and proteins |
|
|
Term
| What is the function of the Golgi apparatus? |
|
Definition
| Processes and packages proteins |
|
|
Term
| What is the function of the rough endoplasmic reticulum (RER)? |
|
Definition
|
|
Term
| What is the main difference between bronchitis and emphysema? |
|
Definition
| Bronchitis affects the bronchi, emphysema affects the alveoli |
|
|
Term
| What is the medical term for the death of heart muscle tissue which results in a heart attack? |
|
Definition
|
|
Term
| What is the name of fatty deposits in the arteries? |
|
Definition
|
|
Term
| What is the name of the blood vessels that supply the heart muscle with oxygenated blood? |
|
Definition
|
|
Term
| What is the name of the condition where a blood clot forms in an artery? |
|
Definition
|
|
Term
| What is the name of the covalent bonds in polysaccharides? |
|
Definition
|
|
Term
| What is the name of the covalent bonds in triglycerides? |
|
Definition
|
|
Term
| Suggest two organelles you would expect to find in abundance in a cell that produces a lot of protein. |
|
Definition
| Ribosomes, rough endoplasmic reticulum |
|
|
Term
| What is the name of the fibres through which electrical impulses travel from the bundle of His to the heart muscles, causing the ventricular systole? |
|
Definition
|
|
Term
| What is the name of the group of cells in the centre of the heart which receives electrical impulses from the SAN? |
|
Definition
| Atrioventricular node (AVN) |
|
|
Term
| What is the name of the group of cells which transmit electrical impulses that cause heart muscle to contract? |
|
Definition
|
|
Term
| What is the name of the instrument used to separate organelles in cell fractionation? |
|
Definition
|
|
Term
| What is the name of the layer of cells lining the inside of an artery? |
|
Definition
|
|
Term
| What is the name of the muscle fibre through which electrical impulses travel from the AVN to the bottom of the ventricles? |
|
Definition
|
|
Term
| What is the name of the process by which cells are broken down in fractionation? What instrument is used to do it? What is the name of the resulting fluid? |
|
Definition
| Homogenation; homogeniser; homogenate |
|
|
Term
| What is the name of the process by which food moves down the oesophagus, and how does it work? |
|
Definition
| Peristalsis - a series of muscular contractions push the food down the oesophagus |
|
|
Term
| What is the name of the property of the heart that allows it to beat independently of the nervous system? |
|
Definition
|
|
Term
| What is the name of the rough surface of atheroma? |
|
Definition
|
|
Term
| What is the principal risk factor associated with emphysema? |
|
Definition
|
|
Term
| What is the purpose of connective tissue between the atria and ventricles? |
|
Definition
| Insulates the ventricles from the electrical signal from the SAN, preventing them from contracting from the top |
|
|
Term
| What is the purpose of inflammation? |
|
Definition
| Helps to prevent more pathogens from entering a wound and can destroy pathogens and reduce damage |
|
|
Term
| What is the purpose of the atrial systole? |
|
Definition
| To squeeze remaining blood from atria to ventricles once pressure equilibrium is reached |
|
|
Term
| What is the purpose of the atrioventricular valves? |
|
Definition
| Prevent backflow of blood from ventricles to atria |
|
|
Term
| What is the purpose of the semi-lunar valves? |
|
Definition
| Prevent backflow of blood from arteries to ventricles |
|
|
Term
| What is the purpose of the ventricular systole? |
|
Definition
| Pressure in ventricles increases; semi-lunar valves open and blood travels from right ventricle to pulmonary artery and from left ventricle to aorta |
|
|
Term
| What is the purpose of ventilation? |
|
Definition
| To maintain a concentration gradient of oxygen and carbon dioxide between the alveoli and capillaries. |
|
|
Term
| What is the region enclosed by the inner membrane of mitochondria called? |
|
Definition
|
|
Term
| What is the role of antibodies in immunity? |
|
Definition
| They bind to the complementary antigens of invading pathogens and cause them to clump together so that they can be ingested by phagocytosis. |
|
|
Term
| What is the role of memory cells in immunity? |
|
Definition
| Storing the shape of the antigens of pathogens for future infection by the same pathogen |
|
|
Term
| What is the role of plasma cells in immunity? |
|
Definition
| Producing antibodies complementary to the antigens of invading pathogens |
|
|
Term
| What is the role of the smooth endoplasmic reticulum (SER)? |
|
Definition
| Chemical modification of molecules |
|
|
Term
| What is the study of the incidence of disease called? |
|
Definition
|
|
Term
| What is the term for the narrowing of the arteries due to atheroma? |
|
Definition
|
|
Term
| What is the typical resolution of a light microscope? |
|
Definition
|
|
Term
| What is the typical resolution of an electron microscope? |
|
Definition
|
|
Term
|
Definition
| A condition where a blood clot forms in an artery |
|
|
Term
| What molecules react to form a triglyceride? |
|
Definition
| Three fatty acids and a glycerol. |
|
|
Term
| What substance acts as an inflammatory mediator? |
|
Definition
|
|
Term
| What things can cause damage to the endothelium of coronary arteries? |
|
Definition
| Uneven blood flow, high blood pressure, viral infection or chemical pollutants in the blood |
|
|
Term
| What two types of cell do B cells differentiate into? |
|
Definition
| Plasma cells and memory cells |
|
|
Term
| What type of nerves cause heart rate to decrease? |
|
Definition
|
|
Term
| What type of nerves cause heart rate to increase? |
|
Definition
|
|
Term
| When a person starts to breathe out, the percentage of oxygen in the air first exhaled is the same as the percentage of oxygen in the atmospheric air. Explain why. |
|
Definition
| This air is from the nose/trachea/bronchi; gas exchange occurs only in the alveoli. |
|
|
Term
| Where do B lymphocytes develop? |
|
Definition
|
|
Term
| Where do T lymphocytes develop? |
|
Definition
|
|
Term
| Which of the four chambers of the heart produces the greatest blood pressure? |
|
Definition
|
|
Term
| Which side of the heart contains oxygenated blood? |
|
Definition
|
|
Term
| Why can living specimens not be observed under an electron microscope? |
|
Definition
| The sample must be in a vacuum. |
|
|
Term
| Why do electron microscopes have a greater resolving power than light microscopes? |
|
Definition
| The beam of electrons has a smaller wavelength than light. |
|
|
Term
| Why do glandular cells in the salivary glands, for example, have a lot of endoplasmic reticulum? |
|
Definition
| They secrete digestive enzymes so carry out a lot of protein synthesis. |
|
|
Term
| Why do people suffering from TB cough up blood and mucus? |
|
Definition
| TB pathogen multiplies, creating cavities in the lung tissue - parts of lung collapse, allowing fluids to enter the lungs. |
|
|
Term
| Why do phospholipid bilayers form in water? |
|
Definition
| Phospholipids have a hydrophilic head and a hydrophobic tail. |
|
|
Term
| Why do unsaturated fats have a lower boiling point than saturated fats? |
|
Definition
| "Kinks" at sites of C=C double bonds prevent molecules from packing closely together. |
|
|
Term
| Why is the wall of the left ventricle thicker than the wall of the right ventricle? |
|
Definition
| The same volume of blood must be pumped over a much greater distance (the systemic circuit rather than the pulmonary circuit) |
|
|
Term
| Why must electron micrographs be produced in a vacuum? |
|
Definition
| Electrons can be absorbed by air and would not reach the sample |
|
|
