Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 1 biology > 5.1.2-excretion > Flashcards

5.1.2-excretion Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

what is excretion
5.1.2(a)

A

removal of metabolic waste from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are some examples of excretory products
5.1.2(a)

A

-CO2 from respiration
-nitrogen containing compounds eg-urea
-bile compound (excreated as part of faeces)
the rest of faeces IS NOT metabolic waste

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

name 4 examples of excretory organs and what they do
5.1.2(a)

A

-the lungs(CO2)
-the liver
-the kidneys
-the skin (substances can be excreted in the sweat)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the effects of excess co2 on the blood
5.1.2(a)

A

-lead to the pH of the blood becoming more acidic
-this is because of the following chemical reaction
CO2+H2O———>H2CO3
H2CO3———–>H+ +HCO3- (Catalysed by carbonic anhydrase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what helps buffer the pH of the blood
5.1.2(a)

A

H+ binds to haemaglobin forming haemoglonic acid this helps buffer the pH of the blood
however haemoglobinic acid also has a lower affinity for oxygen
CO2 can also combine directly with haemoglobin producing carbaminohaemaglobin which is also unable to bind to O2 normally
this reduces the efficiany of O2 transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what effect does the excess pH have on the blood plasma
5.1.2(a)

A

excess pH can lead to the denaturation of some proteins
however some proteins in the blood plasma can bind to excess H+ ions to buffer that pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how is excess CO2 removed
5.1.2(a)

A

through increased respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

since the body cannot store excess amino acids what process does it do instead
5.1.2(a)

A

deamination
formation of urea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe the process of deamination
5.1.2(a)

A

amino acid + oxygen———>keto acid + ammonia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the problem with ammonia
5.1.2(a)

A

very soluble and toxic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is keto acid used for
5.1.2(a)

A

respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe the formation of urea
5.1.2(a)

A

ammonia + carbon dioxide———> urea + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is good about urea
5.1.2(a)

A

less soluble and toxic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the function of the hepatic artery and how can you tell this
5.1.2(b)

A

-carries oxygenated blood to liver cells
-as blood is entering liver through narrow vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the function of the hepatic portal vein
5.1.2(b)

A

-delivers deoxygenated blood from the digestive system to the liver where the substances are detoxified by liver cells
-blood from gut enters liver through a branched vessel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the function of the hepatic vein
5.1.2(b)

A

-detoxified “clean” blood to the heart
-as blood is leaving liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the function of the bile duct
5.1.2(b)

A

carries bile from the liver to the small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the function of the gall bladder
5.1.2(b)

A

stores bile which aids digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are Kupffer cells and what are they involved with
5.1.2(b)

A

-involved in phagocytosis
-digestion of old RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

3 ways hepatocytes are specialised
5.1.2(b)

A

-many mitochondria for aerobic respiration to produce ATP for metabolic reactions
-SER for cholesterol synthesis
-glycogen granules for glucose storage and release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the 3 functions of the liver
5.1.2(b)

A

-stores glycogen
-detoxification
-break down excess amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how does the liver help store glycogen
5.1.2(b)

A

stores glycogen which helps control blood glucose levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what 2 substances does the liver detoxify
5.1.2(b)

A

-hydrogen peroxide (toxic waste product of respiration)
-ethanol (toxic to nervous system)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

how is hydrogen peroxide detoxified
5.1.2(b)

A

2H2O2——————->2H2O + 02
(catalysed by catalase)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how is ethanol detoxified
5.1.2(b)

A

ethanol—->ethanal—->ethanoic acid—->acetyl coenzyme A (used in respiration)
(catalysed by ethanoic dehydrogenase)

26
Q

gross structure and histology of the kidney
5.1.2(b)

A

in booklet

27
Q

what are the 2 roles of the kidney
5.1.2(C)

A

filter blood-removes harmful waste products
produce urine-controls water potential of the blood (osmoregulation)

28
Q

what is the difference between he afferent and efferent arteriole
5.1.2(c)

A

efferent-carries blood away from the glomerulus
afferent-wider and supplies blood to the nephron

29
Q

How are substances forced into the bowmans capusle
5.1.2(c)

A

Afferent arteriole has a wider diameter than the efferent arteriole which causes a high HSP inside the glomerulus which forces the substances into the Bowmans capsule

30
Q

describe the process of ultrafiltration
5.1.2(c)

A

To pass through the lumen of the Bowmans Capsule substances need to pass through the capillaries endothelium (contains pores called fenestration), basement membrane (fine mesh of collagen fibres and glycoproteins) and podocytes (gaps between podocytes control which substances can be let through). The mixture of substances in the lumen of the Bowmans capsule is known as glomeular filtrate made up of water, glucose, ions and urea. Larger substances eg-RBCs and proteins aren’t let through this is called ultrafiltration.

31
Q

describe the process of selective reabsorption
5.1.2(c)

A

The glomerular filtrate passes through to the proximal convoluted tubule where useful substances eg-water, glucose and ions are reabsorbed into the blood through selective reabsorption

1.Na+ ions are actively transported out of the PCT

  1. This creates a low concentration of Na+ ions in the PCT which establishes a concentration gradient
  2. Na+ ions diffuse from the filtrate into the PCT through a co-transport protein which carries a glucose or amino acid at the same time
  3. glucose and amino acids diffuse from the PCT into the blood
  4. Some water moves from the filtrate into the blood by osmosis
32
Q

describe water reabsorption
5.1.2(c)

A

Filtrate moves into the loop of henle (composed of descending limb and ascending limb.) In the ascending limb Na+ is actively transported from the filtrate into the medulla this creates a water potential gradient and causes water to move out of the descending limb via osmosis. In the medulla Na+ and water are then reabsorbed into the blood.

33
Q

how is the loop of henle a countercurrent mechanism
5.1.2(c)

A

The loss of Na+ from the ascending limb causes the water potential up the ascending limb to increase. The water potential decreases down the descending limb as water is leaving by osmosis-this is called a countercurrent mechanism and maintains a water potential gradient across the loop of
henle.

34
Q

outline the processes in the loop of henle that cause solute conc to increase

A

-ascending limb is impermeable to water
-Na+ diffuses out of the lower part of the ascending limb
-active transport out of the upper part of the ascending limb
-water leaves descending limb by osmosis
-reference to countercurrent multipler

35
Q

how do we then produce urine
5.1.2(c)

A

The glomerular filtrate moves into the distal convoluted tubule and then into the collecting duct. Water is then reabsorbed into the blood. How much is reabsorbed depends on the permeability of these structures.

When the body needs more water the permeability of DCT and collecting duct increase leads to more concentrated urine

When the body needs less water the permeability of DCT and collecting duct decrease leads to less concentrated urine

36
Q

what are some adaptations of the PCT
5.1.2(c)

A
  1. mitochondria to produce ATP
  2. Large number and variety of co-transport proteins
  3. Microvilli to increase the SA for diffusion
  4. Short diffusion distance through one cell
37
Q

what is the gross structure of the kidney
5.1.2(c)

A

in booklet

38
Q

what is osmoregulation
5.1.2(d)

A

homeostatic control of water potential in the blood through the negative feedback mechanism

39
Q

what are osmoreceptors and where are they found
5.1.1(d)

A

detect changes in the bloods water potential
found in the hypothalamus

40
Q

what happens when your blood water potential decreases
5.1.1(d)

A
  1. Osmoreceptors detect the decrease in the blood’s water potential
  2. when an action potential is sent from the hypothalamus This stimulates ADH release from the Posterior pituitary gland
  3. This increases the reabsorption of water by osmosis by increasing the permeability of the collecting duct
  4. This increases the blood’s water potential and produces a smaller volume of more concentrated urine
  5. When the water potential of blood has returned normal the pituitary gland decreases that the secretion of ADH
41
Q

what happens when your blood water potential increases
5.1.1(d)

A
  1. Osmoreceptors detect the increase in the blood’s water potential
  2. when an action potential is sent from the hypothalamus This reduces stimulation of ADH release from the pituitary gland
  3. This decreases the reabsorption of water by osmosis by decreasing the permeability of the collecting duct
  4. This decreases the blood’s water potential and produces a larger volume of less concentrated urine
  5. When the water potential of blood has returned normal the pituitary gland increases that the secretion of ADH
42
Q

when water potential is too low what happens after the posterior pituitary gland secretes ADH
5.1.2(d)

A
  1. ADH bind to receptors on the CSM of collecting duct cells
  2. cAMP production increases inside collecting duct cells
  3. inside collecting duct cells aquaporins move and fuse with the plasma membrane
  4. So more water can move from filtrate into tissue fluid
43
Q

how can kidney failure be assessed
5.1.2(e)

A

a decrease in glomerular filtration rate indicated kidney damage

44
Q

how is glomerular filtration rate measured
5.1.2(e)

A

using creatine (waste substance produces by muscles)
high concentration=kidney damage

45
Q

what else in the urine indicates kidney damage
5.1.2(c)

A

proteins shows there been damage to the glomerular filter which prevents larger molecules entering the blood

46
Q

if the GFR is low then the kidneys are not filtering blood quickly enough so…
5.1.2(c)

A

-toxic waste products eg-urea increase in concentration in the blood
-excess water and ions remain in the blood and aren’t excreted. The retention of the ions disrupts the electrolyte balance of the blood

47
Q

what are the factors affecting glomerular filtration rate
5.1.2(e)

A

GFR decreases with age
men have more creatine than women

48
Q

what are the 3 treatments for kidney failure
5.1.2(e)

A

-haemodialysis
-peritoneal dialysis
-kidney transplant

49
Q

what is haemodialysis
5.1.2(c)

A

Passing the patients’ blood through a dialysis machine. Machine contains an artificial partially permeable membrane which separates the blood from the dialysis fluid. The fluid has a similar composition to blood HOWEVER it doesn’t contain urea which ensures glucose doesn’t diffuse out of the blood BUT urea does. To make sure all of the urea is removed the blood and dialysis fluid move in opposite directions (counter-current exchange system). This maintains a concentration gradient.

50
Q

what is added to the blood to prevent it from clotting
5.1.2(e)

A

Heparin

51
Q

what is peritoneal dialysis
5.1.2(e)

A

Takes place inside the body. Dialysis fluid is inserted into the stomach. Substances are exchanged through the lining of the abdomen (peritoneal membrane)

52
Q

what is a difference between haemodialysis and peritoneal dialysis
5.1.2(e)

A

haemodialysis uses a counter current exchange system whereas peritoneal dialysis doesn’t. This is why it has to be repeated 4x a day

53
Q

how does peritoneal dialysis move substances
5.1.2(e)

A

-active transport-as peritoneal walls are made up of living cells so produces ATP for active transport
facilitated diffusion

54
Q

what is a kidney transplant
5.1.2(e)

A

surgeon implants a new kidney and attaches it onto the renal vein, artery and ureter.

55
Q

what are the benefits of kidney transplant
5.1.2(e)

A

-no repeated dialysis
-diet is less limited

56
Q

what are the disadvantages of a kidney transplant
5.1.2(e)

A

-not enough donors
-body may reject transplant
-immunosupressants increase disease susceptibility

57
Q

what are the 3 uses of urine samples
5.1.2(f)

A

-pregnancy tests
-drug tests
-medical diagnosis

58
Q

describe how a pregnancy test works
5.1.2(f)

A

Contains monoclonal antibodies attached to coloured beads. These antibodies are complementary to hCG so bind to hCG
Contains immobilised antibodies that are also complementary to hCG so the hCG antibody complex binds to the immobilised antibody. This creates a blue line.
Contains immobilised antibodies which are complementary to the unbound antibody. This produces a blue line. It acts as a control to show the test is working correctly.

59
Q

describe how a drug test works
5.1.2(f)

A

use antibodies-some drugs are complmentary to the antibody
gas chromatography-Turn urine into gas and identify the different substances in it
Eg-can be used to identify if someone is taking anabolic steroids (used to increase muscle mass)

60
Q

how can you use a urine test for medical diagnosis
5.1.2(f)

A

increase glucose=diabetes
increase nitrites=bacterial infection
increase urea=kidney damage

61
Q

how are anabolic steroids effective when applied to the surface of the skin
5.1.2(f)

A

-skin has a large SA
-steroids are lipid soluble
-so can cross the phospholipid bilayer

Year 1 biology (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions