Topic 1 - Lifestyle, health and risk Flashcards
What are emulsions?
Insoluble liquid droplets suspended in another liquid
What are suspensions?
Insoluble solid particles mixed with a liquid which needs to be stirred to stop it separating
Why does water have a high surface tension?
Its molecules form hydrogen bonds between each other but no such bonds form between the water and the air
What does amphoteric mean?
It can act as both an acid and a base
What is the biological use of water being a solvent?
Allows the chemical reactions within cells to take place in the water in the cell
What is the biological use of water having a high surface tension?
Used in plant transport systems
Life at the surface of ponds
What is the biological use of water being amphoteric?
Acts as a buffer
What are the main components of blood?
Plasma
Erythrocytes (Red blood cells)
Leucocytes (White blood cells)
Platelets
What are the main features of plasma in the blood?
Main component of blood
Consists largely of water
Contains lots of dissolved substances
Contains fibrinogen for blood clotting
What are the main features of red blood cells?
Biconcave High density Contain haemoglobin Formed in red bone marrow of long bones Live for 120 days No nucleus
What are the main features of white blood cells?
Larger than erythrocytes Can change their shape Much lower density than red blood cells Contain nucleus Contain cytoplasm Formed in white bone marrow of short bones or in lymph glands and spleen
What are the main features of platelets?
Fragments of megakaryocytes found in bone marrow
Involved in blood clotting
What are the functions of blood plasma?
Transport digested food products Transport food molecules to cells Transport excretory products Transports hormones Maintain a steady body temperature Act as a pH buffer
How do haemoglobin molecules release oxygen?
Oxygenated blood approaches tissues
Small decrease in partial pressure
Large decrease in % oxygen saturation
Oxygen released
How is carbon dioxide transported to the lungs?
Diffuses into red blood cells
Combines with water -> carbonic acid (catalysed by carbonic anhydrase)
Dissociates to H+ and hydrogencarbonate ions (H2CO3)
Haemoglobin accepts H+ ion
Haemoglobonic acid formed
H2CO3 diffuses out and Cl- in
What substances do the platelets release at a cut?
Serotonin - causes muscle contraction
Thromoplastin
What are the events of blood clotting?
Platelets release thromboplastin
Thromboplastin catalyses prothrombin and Ca2+ into thrombin
Thrombin catalyses fibrinogen into fibrin
Fibrin forms a mesh of fibres trapping particles
Clot forms
Where does the systemic circulation carry blood to and from?
Oxygenated from heart to cells
Deoxygenated back to the heart
Where does the pulmonary circulation carry blood to and from?
Deoxygenated from heart to lungs
Oxygenated back to the heart
What are the advantages of a double circulation system?
Separate oxygenated and deoxygenated blood
Different pressures
Where do arteries carry blood?
From the heart to the cells
What blood do arteries transport?
Most carry oxygenated
Pulmonary to lungs and umbilical from foetus to placenta carry deoxygenated
What are the main features of arteries?
High pressure External layer of tough tissue Middle layer of elastic fibres and smooth muscle Smooth lining Small lumen when unstretched
How does the structure of arteries change closer to the heart?
Larger lumen
More elastin fibres
Larger artery
What are the features of capillaries?
Link arterioles and venules
Thin walls for diffusion (one cell thick)
Large lumen
Where do the veins carry blood?
To the heart
What type of blood do the veins carry?
Most deoxygenated
Pulmonary to heart and umbilical from placenta into foetus carry oxygenated
What two veins carry the blood into the heart?
Inferior vena cava from lower body
Superior vena cava from upper body
What are the main feature of veins?
Relatively large lumen Smooth inner surface Thin layer of smooth muscle with few elastic fibres Outer tough layer Can hold a large volume of blood Contain semilunar valves
What muscle does the heart contain?
Cardiac
What properties does cardiac muscle have?
Doesn’t fatigue
Myogenic
What does the inferior vena cava do?
Carries deoxygenated blood from the lower body to the right atrium
What does the superior vena cava do?
Carries deoxygenated blood from the upper body to the right atrium
What type of blood does the right heart carry?
Deoxygenated
What type of blood does the left heart carry?
Oxygenated
What does the right atrium do?
Receives blood from the great veins
Opens tricuspid valve
Fills right ventricle with blood
What are the main features of the tricuspid valve?
Made of three flaps
Known as atrioventricular valve
Prevents back-flow
Tendinous cords prevent turning inside out
What does the right ventricle do?
Fills with high pressure blood from atrium
Pumps blood into pulmonary artery through semilunar valves
What are the main features of the pulmonary veins?
Returns blood from lungs to left atrium
Low pressure
Which side of the heart is more muscles?
The right side
What artery does the left ventricle pump blood through?
The aorta
What are the three stages of the cardiac cycle?
Atrial systole
Ventricular systole
Diastole
What happens in diastole?
The heart is relaxed
Semilunar valves closed and AV open
Heart fills with blood
What happens in atrial systole?
Atria contracts
Blood forced into ventricle
What happens in ventricular systole?
Ventricle contracts
Blood pumped out of the heart
What is intrinsic rhytmicity?
Where the hearts cells contracts in a rhythm before the heart is formed
What controls the heart rate?
The cardiovascular centre
How does atherosclerosis form?
Endothelial cells damaged
Lipids build-up
Platelets form cap over fatty plague
Where is atherosclerosis more likely to form?
Arteries
What can cause atherosclerosis?
High blood pressure
Smoking
What is an atheroma?
Fatty deposit
What does atherosclerosis cause?
Increased blood pressure (smaller artery)
Aneurysm (weakened artery wall)
Split blood vessels
Stroke
What are the two most common types of heart disease?
Angina and myocardial infarction
What causes angina?
Plague build-up in coronary arteries
Heart muscle gets less oxygen
Heart muscle anaerobically respires
Pain in the chest
How is angina treated?
Low-fat diet Regular exercise Losing weight Not smoking Drugs which cause dilation Heart bypass surgery
What cause a heart attack (Myocardial infarction)?
Blocked coronary artery
What is a clot formed in a blood vessel called?
Thrombosis
What causes a stroke?
Interruption in blood supply to the brain
What are the symptoms of stroke?
Dizziness Confusion Slurred speech Blurred vision Numbness
What are the treatments for strokes?
Clot-busting drugs
What are the macronutrients we need in our diet?
Carbohydrates
Proteins
Fats/lipids
What are the micronutrients we need in our diet?
Mineral salts
Vitamins
Why do we need carbohydrates?
Energy
Broken down into glucose
Why do we need lipids in our diet?
Energy
Excess stored as body fat
Why do we need protein in our diet?
Broken down into amino acids
Some amino acids the body does not make
Why do we need mineral salts?
Calcium - skeleton/ teeth, contraction and clotting
Sodium - nerves to work, contraction and heartbeat
Why do we need vitamin C?
Form connective tissue
Prevent scurvy
What does scurvy cause?
Bleeding gums
Easy bruising
Painful joints
Why do we need fibre?
Holds water
Provides bulk for the intestinal muscles
What are the main features of monosaccharides?
Sugars
(CH2O)n
Join in condensation reaction
What are the main features of disaccharides?
Form in condensation reaction
Glycosidic bond
(C6H10O5)n
What are the main features of sucrose?
Stored in plants like sugar beet/cane
Glucose + fructose
1,4 - glycosidic bond
What are the main features of lactose?
Found in milk
Glucose + galactose
1,4 - glycosidic bond
What are the main features of maltose?
Found in germinating seed like barley
Glucose + glucose
1,4 - glycosidic bond
What are the main features of amylose?
Only 1,4 - glycosidic bonds
Single chain
Forms a spiral
What are the main features of amylopectin?
1,4 - glycosidic bonds and 1,6 - glycosidic bonds
Branched
What reaction breaks disaccharides?
Hydrolysis
What is starch made up of?
Amylose and amylopectin
Can be store of energy or for sudden release
What are the main features of glycogen?
1,4 - glycosidic bonds and 1,6 - glycosidic bonds
Animal starch
Compact
Many side branches
What are the main features of lipids?
Good insulators
Made of three fatty acids and a glycerol
What is glycerol?
Propan-1,2,3-triol
All on same side
How do glycerol and a fatty acids combine?
Esterification/condensation reaction
Ester bond formed
If three fatty acids on - triglyceride
In what reaction do amino acids react together?
Condensation reactions
Peptide bond
What is the formula of an amino acid?
NCC
NH2
H-C-R
COOH
What bonds are in proteins?
Peptide bonds
Hydrogen bonds
Sulphur bridges (R group)
Ionic bonds
What is the primary structure of a protein?
Linear sequence of amino acids in a peptide
What is the secondary structure of a protein?
The repeating pattern in the structure of the peptide chains
a-helix
B-pleated sheet
What is the tertiary structure of a protein?
The 3D folding of the secondary structure
What is the quaternary structure of a protein?
The 3D arrangement of more than one tertiary polypeptide
What are the main features of fibrous proteins?
Little or no tertiary structure
Long, parallel polypeptide chains with occasional cross-linkages forming fibres
Insoluble in water
Tough
What are the main features of globular proteins?
Complex tertiary and maybe quaternary structures
Folded into spherical shapes
Form a colloid
What are the main features of a conjugated protein?
Joined to prosthetic group
Haemoglobin
What are lipoproteins?
Proteins conjugated with lipids
Low-density (LDL) or HDL
What is the basal metabolic rate?
Minimum energy needed to live
How is BMI calculated?
Weight (kg) / height^2 (m^2)
What is risk?
The probability that a particular event will happen
What is valid?
Properly designed to answer the questions being asked
What is reliable?
Repeatable
What factors can affect risk of CVD?
Smoking Weight Exercise Stress Diet - want less LDL and more HDL
What are drugs that reduce blood pressure?
Antihypertensives
What are some antihypertensives and how do they work?
Diuretics - Urinate - remove excess so less blood
Beta blockers - slow heart rate
Sympathetic nerve inhibitors - prevent rise in blood pressure
ACE inhibitors - prevent angiotensin from being produced - no constriction
How do statins work?
Lower cholesterol levels
Improve LDL and HDL balance
Reduce inflammation
What are side effects of statins?
Very small chance of fatal muscle inflammation
Small chance of liver failure
What are plant stanols (sterols)?
Similar to cholesterol
Reduce amount of cholesterol absorbed
What are some anticoagulants and what do they do?
Warfarin - Interferes with prothrombin production
Platelet inhibitor drugs- make platelets less sticky
What are colloids?
Solutions with larger solute particles than solvent particles
