glucose metabolism + homeostasis

Question 1

diff between metabolism and digestion?

Answer 1

digestion is like taking apart the old house to make new building blocks

metabolism = the many different systems in the house working together to keep it running smoothly

Question 2

which 2 organs only use glucose for energy?

Answer 2

brain
retina

Question 3

how do cells metabolise glucose?

Answer 3

using oxygen
to be able to extract energy from carbs
for body cells
through the process of respiration

Question 4

what is the sole nutrient/ fuel for red blood cells?

Answer 4

glucose

Question 5

1g of glucose provides how many

Answer 5

3.75 Kilocalories of energy

Question 6

how is glucose metabolised?

Answer 6

through respiration
krebs cycle
glucose molecule is broken down into:

2 pyruvate molecules
1 ATP

Question 7

importance of balancing sugars in our body?

Answer 7

+ sugar in body = diabetic

Question 8

how are sugars balanced in our body?

Answer 8

insulin- beta cells
glucagon- alpha cells
from islets of langerhans

Question 9

which body cells are most sensitive to insulin?

Answer 9

adipose tissue
skeletalmuscle cells
liver cells

have more receptors for insulin

Question 10

how does insulin regulate amount of glucose in our body cells?

Answer 10

b cells found in islets of langerhans
secrete insulin
stimulates uptake of glucose by body cells
insulin sensitivity exists across whole body

Question 11

how does glucagon regulate amount of glucose in our body cells?

Answer 11

found in a cells
increases glucose in blood stream
through gluconeogenesis
where glucagon stimulates liver to break down glycogen into glucose
and send out into blood stream

Question 12

glucagon and insulin are?

Answer 12

antagonists

Question 13

structure of insulin?

Answer 13

formed of 2 chains (carboxylic chains + b chain)
connected by disulphide bond

translated by RNA into pro pre insulin = 1 chain
which gets into cells of RER
once inside RER
packaged into PRO insulin (loses parts of peptides)= 3 chains

a chain
b chain
c chain= small peptide which joins them together

moves to be further packaged into trans golgi apparatus
LOSES C peptide

becomes 2 chains connected together with disulphide bond

Leaves cells by exocytosis

• golgi apparatus releases insulin + cleaved c peptide (has no known biological function) into blood stream

Question 14

how does insulin stimulate uptake of glucose by body cells?

Answer 14

stimulates GLUT4
stimulates uptake of glucose
via cells which have insulin receptors

Question 15

clinical application of insulin stimulating glucose uptake by body cells?

Answer 15

GLUT4 forms basis of hypoglycaemic drugs (used in type 2 patients)
drugs phosphorylate GLUT4
-> makes it more available
lowers insulin sensitivity of patient

Question 16

normal glucose levels in body when fasting?

Answer 16

80-90mg/ 100ml
in random measurements (not HbA1c)

Question 17

normal glucose levels in body after a meal?

Answer 17

120-140mg/100ml

if above this= diabetic
insulin main hormone for protection against diabetes

Question 18

what is type 1 diabetes?

Answer 18

complete damage to pancreas
autoimmune/ genetic factors lead to:
complete absence of insulin

Question 19

type 1 diabetic patients need?

Answer 19

need insulin replacement for life

Question 20

what is type 2 diabetes?

Answer 20

deals with insulin sensitivity
(depends on number of receptors present on body cells’ surfaces
ability of cells to respond to insulin and uptake glucose)

Question 21

initial treatment for people with insulin sensitivity?

Answer 21

need to improve cells’ insulin sensitivity
can take:
- oral hyp

Question 22

initial treatment for people with insulin sensitivity?

Answer 22

drugs need to improve cells’ insulin sensitivity
can take:
- oral hypoglycaemic
- modifying edit

Question 23

the effect on insulin deficiency on cells extracellularly?

Answer 23

insufficient insulin
too much glucose in blood
extracellular hyperglycaemia (outer environment of cells)
->above renal threshold, body tries to get rid by glucose coming out of urine (1st symptom of diabetes)

-causes polyurea (need to go to toilet more frequently, polydipsia, loss of potassium + nitrogen

leads to hyperosmosis extracellular
-> water gets drawn out of cells
= dehydration of actual cells
if gets out of hand, leads to HYPERGLYCAEMIC coma

Question 24

effect of insulin = intracellular hypoglycaemia, effects of this?

Answer 24

causes gluconeogenesis
more glucose gets formed in cells
they are deprived of glucose + can’t take it up from outside of cell

leads to:
- LESS protein synthesis
some protein-> changes into glucose

• weakness
• general lethargy
• LESS immunoglobulins
  patient = more prone to infections
  + impaired wound healing
• breakdown of fats
  -> leads to high levels of ketones
  = diabetic ketoacidosis
  = weight loss

Question 25

why is diabetic ketoacidosis bad?

Answer 25

= buildup of ketones in the bloodstream
= toxic in high levels
can lead to coma/ death

Question 26

symptoms of diabetes? (10)

Answer 26

frequent infections causes itching in genital organs

Question 27

microvascular complications of diabetes? (6)

Answer 27

• xerestomia
• retinopathy (eventual blindness)
• nepropathy
• renal failure
• neuropathy
• peripheral nerve damage (feel numbness in peripheries)
  -> hit their toes + don’t feel anything

Question 28

macrovascular complications of diabetes? (8)

Answer 28

• stroke
• ischaemia
• cognitive impairment
• angina
• coronary disease
• CV ischaemia
• heart attacks
• diabetic foot/ ulcers (major causes for amuptations/ death in diabetics)

Question 29

what does long term hyperglycaemia around endothelial lining of the arteries leads to?

Answer 29

end arthritis obliterans

= damage of blood vessels because of presence of glucose
leads to hyperglycaemia around endothelial lining of arteries/ veins/ capillaries
-> damage of wall

which helps deposition of cholesterol plaque on blood vessel walls

when happens in small vessels= microvascular
when happens in major vessels = macrovascular

Question 30

dental complications of diabetes are?

Answer 30

MICROVASCULAR

1) tiny vessels in salivary glands are damaged
acini are damaged
= xerestomia

4) -> PD, loss of teeth, + infection rate

2) infections
3) impaired + delayed healing of wounds in mouth

Question 31

our role as dentists?

Answer 31

• encourage to have regular hygiene visits
• need to do regular perio checks (PD is a major issue with diabetes)

Question 32

people with uncontrolled diabetics can wake up and find what?

Answer 32

tooth on pillow!