4.5: Co-transport and absorption of glucose in the ileum

Question 1

The epithelial cells lining the ileum possess what?

Answer 1

The epithelial cells lining the ileum possess microvilli

Question 2

The epithelial cells lining the ileum possess microvilli.

What are microvilli?

Answer 2

Microvilli are finger-like projections of the cell-surface membrane about 0.6 μm in length

Question 3

The epithelial cells lining the ileum possess microvilli.
Microvilli are finger-like projections of the cell-surface membrane about 0.6 μm in length.
The microvilli provide more surface area for what?

Answer 3

The microvilli provide more surface area for the insertion of carrier proteins

Question 4

The epithelial cells lining the ileum possess microvilli.
Microvilli are finger-like projections of the cell-surface membrane about 0.6 μm in length.
The microvilli provide more surface area for the insertion of carrier proteins through which what can take place?

Answer 4

The microvilli provide more surface area for the insertion of carrier proteins through which:
1. Diffusion
2. Facilitated diffusion
3. Active transport
can take place

Question 5

The epithelial cells lining the ileum possess microvilli.
Microvilli are finger-like projections of the cell-surface membrane about 0.6 μm in length.
The microvilli provide more surface area for the insertion of carrier proteins through which diffusion, facilitated diffusion and active transport can take place.
Another mechanism to increase transport across membranes is to increase the number of what in any given area of membrane?

Answer 5

Another mechanism to increase transport across membranes is to increase the number of:
1. Protein channels
2. Carrier proteins
in any given area of membrane

Question 6

The epithelial cells lining the ileum possess microvilli.
Microvilli are finger-like projections of the cell-surface membrane about 0.6 μm in length.
The microvilli provide more surface area for the insertion of carrier proteins through which diffusion, facilitated diffusion and active transport can take place.
Another mechanism to increase transport across membranes is to increase the number of protein channels and carrier proteins in any given area of membrane (increase their what)?

Answer 6

Another mechanism to increase transport across membranes is to increase the number of:
1. Protein channels
2. Carrier proteins
in any given area of membrane (increase their density)

Question 7

As carbohydrates and proteins are being digested continuously, there is normally a greater concentration of glucose and amino acids within what than in the blood?

Answer 7

As carbohydrates and proteins are being digested continuously, there is normally a greater concentration of:
1. Glucose
2. Amino acids
within the ileum than in the blood

Question 8

As carbohydrates and proteins are being digested continuously, there is normally a greater concentration of glucose and amino acids within the ileum than in the blood.
Given that blood is constantly being circulated by the heart, the glucose absorbed into it is continuously being what?

Answer 8

Given that blood is constantly being circulated by the heart, the glucose absorbed into it is continuously being removed by the cells as they use it up during respiration

Question 9

As carbohydrates and proteins are being digested continuously, there is normally a greater concentration of glucose and amino acids within the ileum than in the blood.
Given that blood is constantly being circulated by the heart, the glucose absorbed into it is continuously being removed by the cells as they use it up during respiration.
This helps to maintain what?

Answer 9

This helps to maintain the concentration gradient between the:

1. Inside of the ileum
2. Blood

Question 10

Villi

Answer 10

Villi are 1 mm projections of the wall of the ileum

Question 11

Villi are 1 mm projections of the wall of the ileum, while microvilli are 0.6 μm projections of the cell-surface membrane of what?

Answer 11

Villi are 1 mm projections of the wall of the ileum, while microvilli are 0.6 μm projections of the cell-surface membrane of the epithelial cells that line this wall

Question 12

Villi are 1 mm projections of the wall of the ileum, while microvilli are 0.6 μm projections of the cell-surface membrane of the epithelial cells that line this wall.
Microvilli are therefore more than how many times smaller than villi?

Answer 12

Microvilli are therefore more than 1,000 times smaller than villi

Question 13

Adaptations of the small intestine for absorption are that:

1. It is what?

Answer 13

Adaptations of the small intestine for absorption are that it is long

Question 14

Adaptations of the small intestine for absorption are that:
1. It is long.
It has a large what for efficient absorption?

Answer 14

The small intestine has a large surface area for efficient absorption

Question 15

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is what?

Answer 15

Adaptations of the small intestine for absorption are that it is folded

Question 16

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further does what?

Answer 16

Adaptations of the small intestine for absorption are that it is folded, which further increases its surface area

Question 17

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has what, which are finger-like projections?

Answer 17

Adaptations of the small intestine for absorption are that it has villi, which are finger-like projections

Question 18

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has villi, which are finger-like projections that do what?

Answer 18

Adaptations of the small intestine for absorption are that it has villi, which are finger-like projections that increase the surface area

Question 19

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has villi, which are finger-like projections that increase the surface area.
4. It has a thin what?

Answer 19

Adaptations of the small intestine for absorption are that it has a thin epithelium

Question 20

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has villi, which are finger-like projections that increase the surface area.
4. It has a thin epithelium (what), which is how thick?

Answer 20

Adaptations of the small intestine for absorption are that it has a thin epithelium (inner layer), which is one cell thick

Question 21

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has villi, which are finger-like projections that increase the surface area.
4. It has a thin epithelium (inner layer), which is one cell thick.
What does this do?

Answer 21

This creates a short diffusion pathway

Question 22

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has villi, which are finger-like projections that increase the surface area.
4. It has a thin epithelium (inner layer), which is one cell thick.
This creates a short diffusion pathway.
5. Epithelial cells have what?

Answer 22

Adaptations of the small intestine for absorption are that epithelial cells have microvilli

Question 23

Adaptations of the small intestine for absorption are that:
1. It is long.
The small intestine has a large surface area for efficient absorption.
2. It is folded, which further increases its surface area.
3. It has villi, which are finger-like projections that increase the surface area.
4. It has a thin epithelium (inner layer), which is one cell thick.
This creates a short diffusion pathway.
5. Epithelial cells have microvilli.
6. The villi have a good what?

Answer 23

Adaptations of the small intestine for absorption are that the villi have a good blood supply

Question 24

Co-transport

Answer 24

Co-transport is a special type of active transport

Question 25

Co-transport is a special type of active transport.

Monosaccharides do what this way?

Answer 25

Monosaccharides move across the epithelium of the small intestine into the capillaries in this way

Question 26

Co-transport is a special type of active transport.
Monosaccharides move across the epithelium of the small intestine into the capillaries in this way.
What are too large?

Answer 26

1. Disaccharides
2. Polysaccharides
   are too large

Question 27

Glucose must be moved from what into what?

Answer 27

Glucose must be moved from the:
1. Lumen of the gut
into
2. Epithelial cells

Question 28

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually what in the epithelial cells than in the gut?

Answer 28

But, the concentration of glucose is usually higher in the epithelial cells than in the gut

Question 29

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires what?

Answer 29

Therefore, transport into the cell requires energy

Question 30

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
What have to move glucose across the membrane, due to its size?

Answer 30

Transport proteins have to move glucose across the membrane, due to its size

Question 31

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with what?

Answer 31

Glucose is transported with sodium ions (Na+)

Question 32

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
How do the sodium ions move?

Answer 32

The sodium ions move along a concentration gradient (high to low)

Question 33

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move how?

Answer 33

The:
1. Sodium ions move along a concentration gradient (high to low)
,whereas
2. Glucose molecules move against a concentration gradient (low to high)

Question 34

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
What is the Na+-glucose symporter?

Answer 34

The Na+-glucose symporter is the pump that moves:
1. Glucose
2. Na+
across the epithelial cell membrane together

Question 35

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
The Na+-glucose symporter is the pump that moves glucose and Na+ across the epithelial cell membrane together.
Both Na+ and glucose can bind to the pump, but the binding of one makes the other what?

Answer 35

Both:
1. Na+
2. Glucose
can bind to the pump, but the binding of one makes the other more effective

Question 36

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
The Na+-glucose symporter is the pump that moves glucose and Na+ across the epithelial cell membrane together.
Both Na+ and glucose can bind to the pump, but the binding of one makes the other more effective.
What must bind to the protein before they can be transported across the membrane?

Answer 36

1. 2 glucose molecules
2. 2 Na+ ions
   must bind to the protein before they can be transported across the membrane

Question 37

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
The Na+-glucose symporter is the pump that moves glucose and Na+ across the epithelial cell membrane together.
Both Na+ and glucose can bind to the pump, but the binding of one makes the other more effective.
2 glucose molecules and 2 Na+ ions must bind to the protein before they can be transported across the membrane.
Glucose and Na+ could in theory move back across the membrane the other way, but there is what inside of the cell?

Answer 37

1. Glucose
2. Na+
   could in theory move back across the membrane the other way, but there is a very low concentration of Na+ on the inside of the cell

Question 38

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
The Na+-glucose symporter is the pump that moves glucose and Na+ across the epithelial cell membrane together.
Both Na+ and glucose can bind to the pump, but the binding of one makes the other more effective.
2 glucose molecules and 2 Na+ ions must bind to the protein before they can be transported across the membrane.
Glucose and Na+ could in theory move back across the membrane the other way, but there is a very low concentration of Na+ on the inside of the cell, so it is rare that Na+ will do what?

Answer 38

1. Glucose
2. Na+
   could in theory move back across the membrane the other way, but there is a very low concentration of Na+ on the inside of the cell, so it is rare that Na+ will move into the symporter from this side

Question 39

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
The Na+-glucose symporter is the pump that moves glucose and Na+ across the epithelial cell membrane together.
Both Na+ and glucose can bind to the pump, but the binding of one makes the other more effective.
2 glucose molecules and 2 Na+ ions must bind to the protein before they can be transported across the membrane.
Glucose and Na+ could in theory move back across the membrane the other way, but there is a very low concentration of Na+ on the inside of the cell, so it is rare that Na+ will move into the symporter from this side.
Therefore, glucose does not do what?

Answer 39

Therefore, glucose does not follow

Question 40

Glucose must be moved from the lumen of the gut into the epithelial cells.
But, the concentration of glucose is usually higher in the epithelial cells than in the gut.
Therefore, transport into the cell requires energy.
Transport proteins have to move glucose across the membrane, due to its size.
Glucose is transported with sodium ions (Na+).
The sodium ions move along a concentration gradient (high to low), whereas glucose molecules move against a concentration gradient (low to high).
The Na+-glucose symporter is the pump that moves glucose and Na+ across the epithelial cell membrane together.
Both Na+ and glucose can bind to the pump, but the binding of one makes the other more effective.
2 glucose molecules and 2 Na+ ions must bind to the protein before they can be transported across the membrane.
Glucose and Na+ could in theory move back across the membrane the other way, but there is a very low concentration of Na+ on the inside of the cell, so it is rare that Na+ will move into the symporter from this side.
Therefore, glucose does not follow and we say the import is what?

Answer 40

Therefore:

1. Glucose does not follow
2. We say the import is unidirectional

Question 41

Movement of glucose into the blood:

Glucose molecules move into the blood by the what via what?

Answer 41

Glucose molecules move into the blood by the glucose uniporter via facilitated diffusion

Question 42

Movement of glucose into the blood:
Glucose molecules move into the blood by the glucose uniporter via facilitated diffusion.
The what pump pumps out what in exchange for what?

Answer 42

The Na+/K+ pump pumps out:
1. 3 Na+ ions
in exchange for
2. 2 K+ ions

Question 43

Movement of glucose into the blood:
Glucose molecules move into the blood by the glucose uniporter via facilitated diffusion.
The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via what?

Answer 43

The Na+/K+ pump pumps out:
1. 3 Na+ ions
in exchange for
2. 2 K+ ions
via active transport

Question 44

Movement of glucose into the blood:
Glucose molecules move into the blood by the glucose uniporter via facilitated diffusion.
The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
Therefore, we do not get a high concentration of sodium inside the epithelial cell.
What does the Na+/K+ pump use?

Answer 44

The Na+/K+ pump uses ATPase

Question 45

Movement of glucose into the blood:
Glucose molecules move into the blood by the glucose uniporter via facilitated diffusion.
The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
Therefore, we do not get a high concentration of sodium inside the epithelial cell.
The Na+/K+ pump uses ATPase.
What is ATPase?

Answer 45

ATPase is an enzyme that hydrolyses ATP

Question 46

In the lumen of the ileum, there is a what concentration of glucose and a what concentration of sodium?

Answer 46

In the lumen of the ileum, there is a:

1. Low concentration of glucose
2. High concentration of sodium

Question 47

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by what?

Answer 47

1. Glucose
2. Sodium
   move into the epithelial cell by the Na+-glucose symporter

Question 48

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via what?

Answer 48

Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport

Question 49

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be what?

Answer 49

In the Na+-glucose symporter, the:
1. Glucose
2. Sodium
molecules must be together

Question 50

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a what concentration of glucose and a what concentration of sodium?

Answer 50

In the epithelial cell, there is a:

1. High concentration of glucose
2. Low concentration of sodium

Question 51

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by what?

Answer 51

Glucose moves into the blood by the glucose uniporter

Question 52

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via what?

Answer 52

Glucose moves into the blood by the glucose uniporter via facilitated diffusion

Question 53

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, how?

Answer 53

Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time

Question 54

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a what concentration of glucose?

Answer 54

In the blood, there is a what low concentration of glucose

Question 55

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a low concentration of glucose, because what?

Answer 55

In the blood, there is a low concentration of glucose, because blood is a stream, constantly moving

Question 56

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a low concentration of glucose, because blood is a stream, constantly moving.
In the blood, there is also a what concentration of what?

Answer 56

In the blood, there is also a low concentration of sodium

Question 57

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a low concentration of glucose, because blood is a stream, constantly moving.
In the blood, there is also a low concentration of sodium, because what?

Answer 57

In the blood, there is also a low concentration of sodium, because:

1. It is being moved by the Na+/K+ pump
2. Blood is constantly moving

Question 58

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a low concentration of glucose, because blood is a stream, constantly moving.
In the blood, there is also a low concentration of sodium, because it is being moved by the Na+/K+ pump and blood is constantly moving.
When sodium comes into the epithelial cells by the Na+-glucose symporter, what will happen?

Answer 58

When sodium comes into the epithelial cells by the Na+-glucose symporter, its concentration will increase

Question 59

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a low concentration of glucose, because blood is a stream, constantly moving.
In the blood, there is also a low concentration of sodium, because it is being moved by the Na+/K+ pump and blood is constantly moving.
When sodium comes into the epithelial cells by the Na+-glucose symporter, its concentration will increase, but we need the concentration of it in the epithelial cell to be low, so that what will keep happening?

Answer 59

When sodium comes into the epithelial cells by the Na+-glucose symporter, its concentration will increase, but we need the concentration of it in the epithelial cell to be low, so that the:
1. Na+-glucose symporter
2. Glucose uniporter
will keep happening

Question 60

In the lumen of the ileum, there is a low concentration of glucose and a high concentration of sodium.
Glucose and sodium move into the epithelial cell by the Na+-glucose symporter via co-transport.
In the Na+-glucose symporter, the glucose and sodium molecules must be together.
In the epithelial cell, there is a high concentration of glucose and a low concentration of sodium.
1. Glucose moves into the blood by the glucose uniporter via facilitated diffusion, one glucose molecule at a time.
2. The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
In the blood, there is a low concentration of glucose, because blood is a stream, constantly moving.
In the blood, there is also a low concentration of sodium, because it is being moved by the Na+/K+ pump and blood is constantly moving.
When sodium comes into the epithelial cells by the Na+-glucose symporter, its concentration will increase, but we need the concentration of it in the epithelial cell to be low, so that the Na+-glucose symporter and the glucose uniporter will keep happening, so there is what?

Answer 60

Na+-glucose symporter, its concentration will increase, but we need the concentration of it in the epithelial cell to be low, so that the:
1. Na+-glucose symporter
2. Glucose uniporter
will keep happening, so there is the Na+/K+ pump

Question 61

Movement of glucose into the blood:
Glucose molecules move into the blood by the glucose uniporter via facilitated diffusion.
The Na+/K+ pump pumps out 3 Na+ ions in exchange for 2 K+ ions via active transport.
Therefore, we do not get what?

Answer 61

Therefore, we do not get a high concentration of sodium inside the epithelial cell