Unit 1: Risk, Health, and Lifestyle Flashcards
What do carbohydrates consist of?
A chain of single units called saccharides contains only carbon, hydrogen and oxygen.
What id the difference between different types of saccharides?
Monosaccharides= single sugar monomer Disaccharide= two monosaccharides Polysaccharides= many monosaccharides
How are di and polysaccharides formed
Monosaccharides join to form di and polysaccharides through a condensation reactions (a water molecule is released). Glycosidic bonds are formed. It can be broken by adding water (hydrolysis)
Give 2 examples of monosaccharides and their function.
Glucose has six carbon atoms and is the main substrate for respiration.
Ribose has five carbon atoms and is a component of DNA and RNA.
Give three examples of disaccharides and their component of monosaccharides.
Maltose (two glucose molecules)
Sucrose (glucose and fructose)
Lactose (glucose and galactose)
Give two examples of polysaccharides and their function
Glycogen (animals) and starch (plants). They are both energy storing molecules
Structure of glycogen and its function
Highly branched, this means that the molecule can be easily hydrolysed to release energy quickly.
Relate starch’s structure to its function.
Mixture of two polysaccharides.
Amylose= coiled to make the molecule compact, so large amounts of it can be stored.
Amylopectin= highly branched, so energy can be released quickly.
How is a triglyceride formed
One molecule of glycerol forms ester bonds with three fatty acids through a condensation reaction.
How to differentiate between saturated and unsaturated fats.
Saturated fats have no C=C bonds. They are solid at room temperature due to strong intermolecular forces.
Unsaturated fats have one or more C=C bonds and are liquid at room temperature due to weak intermolecular forces.
What is meant by a high-density lipoprotein?
Made of triglycerides from unsaturated fats combined with protein. They reduce blood cholesterol levels by transporting it to the liver to be broken down. They are know as the ‘good’ lipoproteins.
What is meant by low-density lipoprotein?
Made of triglycerides from saturated fats combined with a protein. These block receptor sites, reducing the cholesterol absorption. These are know to be the ‘bad’ lipoproteins.
How do LDLs contribute to the risk of cardiovascular disease?
The high blood cholesterol levels caused by LDLs leads to the formation of plaques (atherosclerosis). This is a casual relationship (as one increases the risk increases)
Describe the properties of water.
It is essential for all metabolic processes. One oxygen and two hydrogens, with covalent bonds. All water molecules are held together by strong hydrogen molecules. Due to their polarity and ability to form hydrogen, excellent solvent for polar as well as ionic substances. High specific heat capacity (temperature stabiliser in living bodies). High vaporisation as heat sinks for living bodies- cooling. It is an excellent lubricant providing cushion effect on vital organs. Ideal for transporting and reaction medium. Dissolve- electrostatic forces broken
The veins, arteries and valves going in a clockwise direction of the heart
Pulmonary artery, pulmonary vein, atrioventricular valve, semi-lunar valves, cords (valve tendons), semi-lunar valves, atrioventricular value, inferior vena cava, superior vena cava, artery.
In a clockwise motion, what are the 4 chambers?
Left atrium, left ventricle, right ventricle, right atrium
What do different parts of the heart do (ventricles and valves)?
The left ventricle of the heart has a thicker, more muscular walls than the right ventricle, because it needs to contract powerfully to pump blood all the way around the body, while the right needs to transport it to the lungs, which are close by.
The ventricles have thicker walls than the atria, because they have to push blood out of the heart whereas the atria just need to push the blood a short distance into the ventricles.
The atrioventricular valves link the atria to the ventricles and stop blood flowing back into the atria when the ventricles contract. Cords attach the atrioventricular valves to the ventricles to stop them from being forced up into the atria when the ventricles contract.
Semi-lunar valves link the ventricles to the pulmonary artery and the aorta, and stop the blood flowing back into the heart after the ventricles contract.
How do valves help blood flow in one direction?
The valves only open one way- whether they are open or closed depends on the relative pressure of the heart chamber. If there is a high pressure behind the valves, it is forced open, but if there is high pressure in front of the valve it’s forced shut.
Describe and explain the arteries
They carry the blood from the heart to the rest of the body. They’re thick-walled, muscular and have elastic tissue in the walls to cope with the high pressure cause by the heartbeat. The inner lining (endothelium) is folded, allowing the artery to expand- this also help with high pressure. Narrow lumen (space in centre for blood to flow through).
Describe and explain the veins
They take blood back to the heart. They’re wider that the equivalent arteries, with very little elastic or muscle tissue as the blood is under lower pressure. Veins contain valves to stop the blood flowing backwards. Blood flowing through the veins is helped by contraction of the body muscles around them. (wide lumen)
Describe and explain capillaries
They are the smallest of the blood vessels. They were metabolic change occurs- substance are exchanged between cells and the capillaries. There are a networks of capillaries. These network of capillaries in tissue (called capillary beds), which increase the surface area for exchange. Capillary walls are only one cell thick, which speeds up the rate of diffusion of substances (e.g. glucose and oxygen) into and out of the cells.
