Water and the Blood System

IB Bio SL

What is catabolism and anabolism? (metabolism)

Catabolism: Enzyme catalyzed reactions that convert large molecules (like food) into small molecules, done with hydrolysis which requires a water molecule

Anabolism: Enzyme catalyzed reactions that convert small molecules into large molecules, uses condensation reactions. A water molecule is removed

List the properties of water

• Water molecules are highly cohesive, which allows it to be transported in xylems (adhesion too)

• Polarity, allows it to dissolve polar molecules (universal solvent)

• High specific heat capacity (requires more energy to raise it up by 1C)

• Forms ephemeral hydrogen bonds, which are short lived and is the reason why it has surface tension, why it forms droplets

• High heat of vaporization

• High BP/MP

• Sweat useful as a coolant as hot water is evaporated

What’s the structure of proteins?

• Formed by amino acids (N-C)

• Linked together by peptide bonds

• May consist of one or more polypeptides linked together

• Have a specific shape/conformation/folding

  • Shape determines function

How do valves control the flow of blood through the heart?

• Valves open and close in response to blood pressure/heart contraction/pumping

• Valve prevents backflow and maintains direction of blood flow

  • Valves allow heart chambers to fill and empty, as they open once they are full

What are some causes and consequences of blood clot formation in coronary arteries?

• CHD or coronary heart disease can occur when there is a reduction of oxygen to the heart muscle, as blood clots can stop or slow the flow of oxygenated blood to heart, causing serious problems such as a heart attack or muscle death

• Fatty diet can lead to plaque formation in arteries as it cannot be dissolved

• Plaque can break off, which causes damage that activates blood clot formation

How can the circulatory system transport blood under high pressure?

• Contraction of a ventricle creates high pressure

• Blood at high pressure is carried out through arteries, which have thick, muscular and elastic walls to resist pressure and prevent leaks

• Elastic walls helps push blood

• Narrow lumen maintains pressure

How is the heartbeat initiated?

• It is initiated within the heart- SA node which is located in the right atrium

• Electrical impulses pass over the atria which initiates contraction, uses fibers to Purkinje fibers to do so, extend down the septum

• Impulse is then sent to the AV node, also in the right atrium which delays it so it can go to the muscular ventricles, causing contraction there so they can be in sync.

• When the atria and ventricles contract, pressure increases, which opens the valves so the blood can leave the chamber and go to the rest of the body (systole)

• Afterwards, they go into diastole to fill up for the next cycle

• Can be affected by epinephrine, which increases heart rate, and so can exercise

• Semilunar valves prevent backflow to ventricles, AV valves prevent backflow

What’s the structure for an (un)saturated fatty acid?

• Saturated: C10H20O2

• Unsaturated: C10H18O2 (double bond at carbon 7)

What veins and arteries carry oxygenated blood away and towards the heart?

• Carried away by the aorta (to body)

• Carried towards by pulmonary veins

What veins carry deoxygenated blood away and towards the heart?

• Carried away by pulmonary artery (to lungs)

• Carried towards by the vena cava

Describe parts of an ECG

P: voltage from SA node, atrial systole

Q: AV node sends impulse

QRS: Impulse moves down Purkinje fibers, ventricles in systole

T: AV node repolarizing, about to send the next impulse

How does a defibrillator restore normal heartbeat?

It delivers a shock to the heart, causing the SA node to send the correct electrical impulse.

Outline the flow of blood to the heart

Oxygenated blood leaves lungs → Pulmonary vein → Left atrium, through left AV valve → Left ventricle, through left semilunar valve → Aorta → Body capillaries → Becomes deoxygenated → Vena cava → Right atrium (thru AV valve) → Right ventricle, through right semilunar valve → Pulmonary artery → Lungs (to become oxygenated)