Dietary starch & glycogen are broken down initially by

Salivary amylase- maltose & intermediary dextrin's

What is maltose, lactose, sucrose converted into?

monosaccharides

Glucose is the substrate that form ?

glycogen

Glycolysis is

Oxidation of glucose to pyruvate. Anaerobic: Pyruvate is converted into lactate

Purpose of carbohydrates

provide energy through oxidation supply carbon for the synthesis of cell components stored chemical energy and form structure

aldehyde group

A chemical group consisting of a carbon double bonded to oxygen and single bonded to hydrogen (must be at end of chain)

ketone group

A chemical group consisting of a carbon double bonded to oxygen (must be in middle of chain)

another term for ketoses and aldoses
capable of being a reducing sugar by?

Transferring electrons to another substance

kyrol carbon

Carbon that is bound to 4 different molecules

Penultimate

2nd to last carbon which determines the D& L configuration

anomeric carbon

the new chiral center formed in ring closure; it was the carbon containing the carbonyl in the straight-chain form

Glycogen is mostly stored in

muscle tissue and
liver: stores for whole body

What does insulin do?

it decreases blood glucose

What do the hormones glucagon, epinephrine, GH, cortisol do in the blood stream?

they increase blood glucose levels

Fasting state:

blood glucose low -> HIGH glucagon -> glycogenolysis + gluconeogenesis

Fed state

blood glucose is high -> HIGH insulin -> glycogenesis + glycolysis

glucagon promotes ___________

phosphorylation of glycogen synthase and phosphorylation of glycogen phosphorylase.

glycogenesis needed:

insulin promotes DEphosphorylation of glycogen synthase and DEphosphorylation of glycogen phosphorylase

=> Insulin can only posstively regulate

glycogen phosphorylase:

rate limiting enzymes of glycogenolysis
Active: phosphorylated / inactive: DEphosphorylated

The endocrine pancreatic known as

- " the islet of langerhas"

hormones produced by cells of the islet of pancreatic alpha-

glucagon, ghrelin

hormones produced by cells of the islet of beta-

insulin, proinsulin,C peptide, amylin

hormones produced by cells of the islet of gamma-

somatostatin

hormones produced by cells of the islet of epsilon-

ghrelin

hormones produced by cells of the islet of F-

pancreatic polypetide

Communication between cell to cell

cells within the islet communication gap junction

Neural communication:

Cholinergic stimulation increases insulin secretion. . Adrenergic will can either increase and decreases insulin . Or inhibitor effect can decrease insulin

Exocrine pancreases

secretase digestive enzymes helps with digestion and prevents malnourishment.

In 1889 Makowski demonstrated that removing the pancreases from the pancreases from the dogs caused ____________

a syndrome resembling T1D.

the four major organs that play roles in fuel metabolism are:

liver
adipose tissue
muscle
brain

The integration of energy metabolism is controlled by:

insulin and glucagon, with the catecholamines: epinephrine & norepinephrine as supporters

Insulin secretion is closely coordinated with the release of

glucagon by pancreatic α cells.

Hormones that control the integration of energy metabolism

1)Insuln
2)Glucagon

Levels in a normal healthy human

-->Plasma glucose is maintained in a range of **120-140 mg/dl
--> Fatty Acids are maintained at a level ABOVE

In the abscence of nutreitnt absorption from the GI Tract

1)Glucosee is supplied primarily by the LIVEr
2)Fatty Acids are primarily from the adipose tissue

Lipogenesis

-->Is promoted by **low insulin**

Glucagon like peptide 1(GLP-1 or Incretin)

-->Will bind to its receptor on beta cells & will stimulate increased release of PREPROINSULIN

Why glucose is not a primary energy fuel in liver

saves glucose for other tissues. prefers to use a-keto acids and FAs

will metabolize some glucose only after a meal (i.e. when [glucose] high)

Insulin

- released under fed conditions

a. lowers blood glucose by promoting synthesis of glycogen, stimulating glycolysis, and inhibiting gluconeogenesis

when is glucagon

- released from pancreas under starved conditions (glucose deficiency)

Glucagon can be stimulated by

epinephrine

when is glucagon elevated

elevates blood glucose by promoting breakdown of glycogen in liver and inhibiting glycogen synthesis

Type I

little or no insulin production.

i. Often due to a viral infection in youth - Antibodies to that virus cross react and destroy beta cells of the pancreas

Type II

strongly associated with obesity, hypertriglyceridemia, and insulin resistance

During anaerobic conditions, Pyruvate must be converted to__________

lactate in order to free an NADH into NAD+ to continue anaerobic glycosis due to lack of O2

Insulin, a key regulatory protein for glucose levels in the body, has a precursor known as _________

proinsulin

The precursor proinsulin is larger than insulin and mainly differs from insulin by the presence of the ____________

C-peptide, which prevents the substance from being degraded immediately in the body.

Normal fasting glucose levels ___________

60-80 mg/dL

Normal glucose levels 2 hours after a meal ___________

100-150

Normal insulin levels 2 hours after a meal ___________

3-8 U/mL

Normal glucose levels

72-80

hyperglycemias glucose levels

>125

hypoglycemia glucose levels

< 30-45

Beta cells are the only site of ____________

insulin synthesis in mammals

location of cell types

Insulin-expressing b-cells are often in the core of the islet while glucagon-expressing a-cells are in the periphery

Insulin inhibits ____________

glucagon and SST release

what is secreted into the blood by the b cell?

When the beta cell is appropriately stimulated, insulin is secreted from the cell by exocytosis and diffuses into islet capillary blood. C peptide is also secreted into blood, but has no known biological activity.

influences of beta cells?

glucose, ACh, GIP/GLP-1, NA noradrenaline- which inhibits

GLYCOGENOLYSIS

breakdown of glycogen to glucose,e.g. stimulated by glucagon or adrenaline

GLUCONEOGENESIS

formation of glucose from non- carbohydrate precursors (amino acid, glycerol, lactate)

The insulin mRNA is translated as a single chain precursor called _____________

preproinsulin

what do c peptides do?

is a sign that your body is producing insulin. A low level (or no C-peptide) indicates that your pancreas is producing little or no insulin

glycogenesis

glucose converted to glycogen

During a brief fast __________

glycogen and glucose goes up and glucogenesis is synthesized into glucose

During a prolonged fast ____________

gluconeogenesis is the sole source of energy

As insulin binds to α-chain the receptors undergo a ____________

conformation change leading to ATP binding

alpha chains are

entirely extracellular and house insulin binding domains

beta chains

penetrate through plasma membrane

What does GLUT 4 do?

is an insulin-regulated glucose transporter that is responsible for insulin-regulated glucose uptake into fat and muscle cells.

effects of glucose on the liver

The liver both stores and manufactures glucose depending upon the body’s need. The need to store or release glucose is primarily signaled by the hormones insulin and glucagon.

During a meal, your liver will ____________

store sugar, or glucose, as glycogen for a later time when your body needs it.

Which of the following occurs following absorption of glucose?
A. Glucose is stored as fat in skeletal muscle.
B. Glucose is stored as glycogen in adipose tissue.
C. Glucose is converted to fat in the liver.
D. Glucose is used to make energy by only the brain.
E. Glucose is converted to amino acids in the muscles.

C. Glucose is converted to fat in the liver.

During the absorptive state of metabolism,
A. Liver glycogen is broken down to glucose, which is released into the blood.
B. Glycogen in muscle cells is broken down to glucose, which is used for energy.
C. Lipoprotein lipase breaks down triacylglycerols in adipose tissue capillaries.
D. Fatty acids and glycerol are released from adipose tissue.
E. Lactate and pyruvate secretion into the bloodstream by the muscles increases.

C. Lipoprotein lipase breaks down triacylglycerols in adipose tissue capillaries.

Which of the following tissues is most dependent upon a constant blood supply of glucose?
A. liver
B. brain
C. adipose
D. skeletal muscle
E. cardiac muscle

B. brain

Gluconeogenesis is stimulated by decreased levels of:
A. epinephrine.
B. insulin.
C. glucocorticoids.
D. growth hormone.
E. glucagon.

B. insulin.

Which event occurs during exercise but NOT during fasting?
A. increased breakdown of triglycerides
B. increased glycogenolysis
C. increased glucose uptake by muscle
D. increased fatty acid oxidation
E. increased cortisol secretion

C. increased glucose uptake by muscle

Which is a symptom of untreated type 1 (insulin-dependent) diabetes mellitus?
A. low plasma ketones
B. increased blood volume
C. decreased respiration
D. hyperglycemia
E. increased plasma insulin

D. hyperglycemia

In subjects with type 2 (non-insulin-dependent) diabetes mellitus, which of these occurs?
A. Pancreatic beta cell responses to increased plasma glucose concentration are normal.
B. Target tissues respond poorly to insulin.
C. Hypoglycemia is typically the first symptom.
D. Severe ketoacidosis is common.

B. Target tissues respond poorly to insulin.

Which factor, when increased, increases metabolic rate to the greatest extent?
A. skeletal muscle activity
B. mental activity
C. dietary caloric intake
D. environmental temperature
E. blood glucose levels

A. skeletal muscle activity

A person who is hypothyroid would be expected to:
A. have an increased basal metabolic rate.
B. have reduced tolerance for cold temperatures.
C. lose body weight.
D. be restless and irritable.
E. have symptoms similar to over-activation of the sympathetic nervous system.

B. have reduced tolerance for cold temperatures.

The subjective feeling of hunger is stimulated when:
A. plasma insulin concentration increases.
B. plasma ghrelin concentration decreases.
C. plasma leptin concentration decreases.
D. plasma glucose concentration increases.
E. body temperature increases.

C. plasma leptin concentration decreases.

Most of the triglycerides absorbed as chylomicrons are ultimately stored as fat in the adipose tissue.

TRUE

During the absorptive state, there is net synthesis of fat, glycogen, and protein, but this process is reversed during the postabsorptive state.

TRUE

Most of the energy used by the body during fasting is provided by gluconeogenesis.

FALSE

The major energy sources for non-nervous tissue during the postabsorptive period are fatty acids and ketones.

TRUE

Metabolic acidosis caused by excessive blood levels of ketones is one of the harmful consequences of untreated type 1 (insulin-dependent) diabetes.

TRUE

Which correctly describes an action of the hormone insulin?
A. It increases the uptake and utilization of glucose by muscle and adipose tissue cells.
B. It is required for the uptake and utilization of glucose by nervous tissue.
C. It decreases the uptake of amino acids by muscle cells.
D. It stimulates the breakdown of glycogen in the liver.
E. It inhibits the action of lipoprotein lipase in the capillaries of adipose tissue.

A. It increases the uptake and utilization of glucose by muscle and adipose tissue cells.

Glucagon secretion is stimulated by:

hypoglycemia and high plasma epinephrine concentration.

The major metabolic effects of glucagon include:

A. stimulating glycogenolysis and gluconeogenesis in the liver.

Which of the following is a major metabolic effect of glucagon?

increased glycogenolysis in liver

For type II diabetes as ________

body weight increases furtherer so does the degree of insulin resistance

Type II diabetes makes __________

90% of the diabetes rate in America

Which of the following is NOT a symptom that is associated with untreated type 1
diabetes mellitus (insulin-dependent diabetes mellitus)?
A. hypoglycemia
B. metabolic acidosis
C. dehydration
D. glucosuria (glucose in urine)
E. increased lipolysis

A. hypoglycemia

Glucagon secretion is stimulated by:
A. hypoglycemia and parasympathetic nerve firing.
B. hyperglycemia and a high concentration of epinephrine.
C. high plasma epinephrine and high plasma incretin concentrations.
D. hypoglycemia and high plasma epinephrine concentration.
E. hyperglycemia and high plasma incretin concentration.

D. hypoglycemia and high plasma epinephrine concentration.

How long does it take to diagnose adult hypoglycemia?

By 72-hr fast in the hospital. The sample (glucose, insulin, proinsulin and c peptide) is drawn every 6 hours.

Testing for glucose

- Plasma is used routinely, not whole blood (must be refrigerated and spun down within 20-30 minutes)

- WB is unstable at room temperature because on-going cellular usage of glucose

Hexokinase method

dominant laboratory method of measuring glucose

Plasma glucose in newborns

Reference ranges fasting (between feeding)
-term infants: 30-60 mg/dL
- preemies: 20-60 mg/dL

Plasma glucose in adults

Sample fasting

:74-106 mg/dL

Plasma glucose in children

: 60-100 mg/dL

Glucose oxidase (GO) method

-method incorporated into qualitative urine dipstick methods ('true' glucose method)

-no other sugars will react other than b-D-glucose

-Color rxn: Trinder reaction (measures peroxide)

Glucose monitoring is the measuring _________

the capillary blood

During fasting, ketones produced by the liver:
A. are a waste product of amino acid metabolism that the kidneys must excrete.
B. can be used by the brain as an energy source.
C. are a by-product of anaerobic metabolism.
D. are converted to fatty acids and released into the blood.
E. are used to synthesize glucose by gluconeogenesis.

B. can be used by the brain as an energy source.

The major energy sources for non-nervous tissue during the postabsorptive period are fatty acids and ketones.

TRUE

During anaerobic conditions, Pyruvate must be converted to ________________

lactate in order to free an NADH into NAD+ to continue anaerobic

Glycated HbA1c-

represent integrated glucose levels over the preceding 6 to 8 weeks

HbA1c is recommended to be used __________

to help monitor DM glycemic control some methods- problem with variants

hba1c

The A1C test—also known as the hemoglobin A1C or HbA1c test—is a simple blood test that measures your average blood sugar levels over the past 3 months.

hba1c can used to diagnosis __________

prediabetics and diabetes

fructosamine

is a measure of non-enzymatic glycation of circulating proteins including albumin, globulins, and lipoproteins, has evolved to be a reasonable alternative to HbA1c measurement in situations where HbA1c is not reliable

The fructosamine test shows the average level of glucose in the blood over a period of _____________

two to three weeks, while the hemoglobin A1c test shows that average for the past two to three months.

urine albumins typically is a indicator of __________

renal damage

Microalbuminuria

is defined as urinary albumin excretion of more than 300 mg/G

clinical definition of increased UAE

concentration is(30 to 300 mg/24 hr)

Normal albumin levels are

less than 30 mg/g