Animal tissues, organs and systems flashcards 2.2 (unfinished)

1
Q

What is the main function of the digestive system?

A

To digest food and absorb the nutrients obtained from digestion

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2
Q

What is the role of the pancreas and the salivary gland in the digestive system?

A

The pancreas and the salivary glands are glands which produce digestive juices containing enzymes

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3
Q

What is the role of the stomach in the digestive system?

A

Produces hydrochloric acid - which kills any bacteria present and provides the optimum acidic pH for the protease enzyme to function

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4
Q

What is the role of the small intestine in the digestive system?

A

The small intestine is the site where soluble food molecules are absorbed into the bloodstream

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5
Q

What is the role of the liver in the digestive system?

A

Produces bile (stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently

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6
Q

What is the role of the large intestine in the digestive system?

A

Absorbs water from undigested food, producing faeces

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7
Q

What is the role of enzymes in the digestive system?

A

Enzymes act as biological catalysts which speed up the rate of biological reactions (the breakdown of food) without being used up

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8
Q

How does the shape of an enzyme affect its function?

A

Enzymes have a specific active site which is complementary to their substrate

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9
Q

What is metabolism?

A

The sum of all the reactions in a cell or organism

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10
Q

What types of metabolic reactions do enzymes catalyse?

A
  • Building larger molecules from smaller molecules e.g. glucose to starch
  • Changing one molecule to another e.g. glucose to fructose
  • Breaking down larger molecules into smaller molecules e.g. carbohydrates to glucose
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11
Q

What is the lock and key hypothesis of enzyme function?

A

The shape of the enzyme active site and the substrate are complementary, so can bind together to form an enzyme-substrate complex

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12
Q

How does temperature affect enzyme action?

A

Up to a certain point, increasing temperature increases enzyme action, as molecules have a higher kinetic energy. Above a certain temperature, the shape of the active site is altered and the enzyme becomes denatured, so it can no longer catalyse the reaction. The optimum temperature is around 37°

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13
Q

How does pH affect enzyme function?

A

The optimum pH for most enzymes is 7 (apart from proteases in the stomach). If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work

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14
Q

Where are carbohydrases, proteases and lipases produced in the body?

A
  • Carbohydrases: amylases - salivary gland and pancreas, maltase - small intestine
  • Proteases: pepsin - stomach, others - pancreas and small intestine
  • Lipases: pancreas and small intestine
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15
Q

What is the role of carbohydrases in the digestive system?

A

Carbohydrases break down carbohydrates into monosaccharides and disaccharides. Amylase breaks down starch into maltose, and maltase breaks down maltose into glucose

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16
Q

What is the role of proteases in the digestive system?

A

Proteases break down proteins into amino acids

17
Q

What is the role of lipases in the digestive system?

A

Lipases break down lipids into fatty acids and glycerol

18
Q

How are the products of digestion used?

A

They are used to build bigger molecules such as carbohydrates and proteins. Glucose is used as a substrate in respiration

19
Q

Where is bile made and stored in the body?

A

Bile is made by the liver and stored in the gallbladder

20
Q

What is the role of bile in the digestive system?

A
  • Bile is an alkaline substance which neutralises the hydrochloric acid secreted by the stomach
  • Bile emulsifies lipids to form droplets - this increases the surface area for the lipase enzyme to work on
21
Q

What is the heart?

A

An organ that pumps blood around the body

22
Q

What is the purpose of the circulatory system?

A

Carries oxygen and other useful substances to bodily tissues, and removes waste substances

23
Q

How does the double circulatory system work?

A

One pathway carries blood from the heart to the lungs - where the gaseous exchange of oxygen and carbon dioxide takes place
- One pathway carries blood from the heart to the tissues

24
Q

Where does blood pumped by the right ventricle go?

A

The lungs

25
Q

Where does blood pumped by the left ventricle go?

A

Body tissues

26
Q

Why is the double circulatory system important?

A

It makes the circulatory system more efficient - for example, oxygenated blood can be pumped around the body at a higher pressure by the left ventricle

27
Q

How many chambers does the heart have and what are they called?

A

4 - right atrium, right ventricle, left atrium, left ventricle

28
Q

Why is the wall of the left ventricle thicker?

A

The left ventricle has to pump blood at a higher pressure around the body

29
Q

What are the four main blood vessels associated with the heart?

A
  • Aorta (left) - carries oxygenated blood from the heart to the body
  • Pulmonary vein (left) - carries oxygenated blood from the lungs to the heart
  • Vena cava (right) - carries deoxygenated blood from the body to the heart
  • Pulmonary artery (right) - carries deoxygenated blood from the heart to the lungs
30
Q

What is the purpose of valves in the heart?

A

Prevents the backflow of blood

31
Q

What is the purpose of coronary arteris?

A

Coronary arteries supply the heart muscle with oxygenated blood

32
Q

Describe the process of blood flow through the heart

A
  • Blood enters the right atrium via the vena cava, and the left atrium via the pulmonary vein
  • The atria contract, forcing blood into the ventricles and causing valves to shut
  • After the ventricles contract, blood in the right ventricle enters the pulmonary artery (to the lungs) and blood in the left ventricle enters the aorta (to the body)
33
Q

What is the approximate value of the natural resting heart rate?

A

70 beats per minute

34
Q

How is the heart rate controlled?

A

Heart rate is controlled by a group of cells in the right atrium which act as a pacemaker.
They release waves of electrical activity which cause the heart muscle to contract

35
Q

How can an abnormal heart rhythm be treated?

A

Irregular heart rhythms can be treated using an artificial pacemaker, which sends out electrical signals to correct the heart’s rhythm

36
Q

What are the three types of blood vessel in the body?

A
  • Arteries
  • Veins
  • Capillaries
37
Q

How are arteries adapted for their function?

A
  • Function: carry blood away from the heart
  • Thick muscle layer - adds strength to resist high pressure
  • Thick elastic layer - allows arteries to stretch and recoil - in order to withstand high pressure
38
Q

How are veins adapted for their function?

A
  • Function: carry blood towards the heart
  • Wide lumen - enables low pressure
  • Valves - prevent backflow of blood