Quiz 5 Flashcards
packet 6c until packet 7
type 1 vs type 2 diabetes?
T1D: absolute or near absolute insulin
deficiency which means glucose transport proteins do not relocate to the cell membrane and then glucose remains in the blood
T2D: relative insulin insufficiency, release of insulin is low relative to the elevated
levels of glucose in the blood (caused by insulin resistance), most prevalent form of diabetes
both result in hyperglycemia and metabolic dysfunction
what are the risk factors of T2D?
genetics: relative, obesity, or ethnicity
age: 30 and 50 year old onset
how does obesity lead to insulin resistance?
- adipose tissue functions as an endocrine gland to produce a variety of hormones and signaling proteins collectively referred to as adipokines.
- accumulation of body fat causes adipocytes to become enlarged beyond capacity which leads to an increase in the
production and release of pro-inflammatory adipokines - altered levels of inflammatory adipokines may cause insulin resistance
why do some people with T2D require exogenous insulin?
relative lack of insulin (insulin producing cells are unable to produce enough insulin relative to blood glucose needed to lower blood glucose)
hyperglycemia may cause pancreatic inflammation, which may decrease
insulin production
how is T1D unique?
typical age of onset childhood and adolescence, accounts for 5-10% cases diabetes, is an autoimmune disease where immune system produces antibodies which attack and destroy beta cells (insulin
producing cells) of the pancreas
as insulin levels decrease then blood glucose is allow to increase
what are the unique symptoms of T1D compared to T2D?
nausea and vomitting, fruity breath, rapid weight loss, and ketosis
what happens in T1D without insulin?
hyper-catabolic state: rapid breakdown of muscle proteolysis) and stored fat (lipolysis) which leads to rapid weight loss, ketogenesis (ketone formation) increases, as fatty acids are rapidly broken down and converted into ketones, excessively high levels of ketones in blood can lower pH (diabetic ketoacidosis)
what does an A1c test tell you?
indicates overall blood glucose management
glycated hemoglobin is a form of hemoglobin that has glucose attached, a certain amount of hemoglobin has
glucose attached, but elevated A1c
means a high percentage of
hemoglobin with glucose attached (%)
Elevated A1c (>7 mg/dL) indicates
poor control of blood glucose, elevated A1c associated with increased risk of long-term complications associated with diabetes
what are complications associated with long term diabetes?
over time, elevated blood glucose can cause vascular and nerve damage:
cardiovascular disease, heart attacks, strokes, amputation, neuropathy (nerve damage), numbness, pain, nephropathy (kidney damage), impaired filtration, dialysis, retinopathy (eye damage)
what is gestational diabetes?
hyperglycemia: mother exposes fetus high levels of glucose, fetal pancreas increases
insulin release, increases fat stores fetus, increased risk large gestational age
and macrosomia (large body), increases risk C-section and Type 2 diabetes mother and child
what is dietary protein used for?
dietary protein is digested and the resulting amino acids are used to synthesize proteins (AA linked by peptide bonds form peptides, and then polypeptides and then a functional protein)
what is the structure of amino acids?
all amino acids consist of a nitrogen-containing amino group (NH3+), a central (alpha) carbon, a carboxyl group (COOH-), and a side-chain “R” (functional group)
essential vs non-essential amino acids
essential: if cells cannot make the R group on the amino acid
non-essential: if cells can make the R group on the amino acid
what are the four levels of protein structure?
primary: the primary structure of a protein is determined by the genetic code in our
DNA, consists of a unique sequence and
number of amino acids that make up a
polypeptide chain
secondary: positive charge on amino groups and negative charge on carboxyl
groups attract each other, cause the
primary structure to fold in organized and predictable patterns that are held together by hydrogen bonds (a-helix and B-folded sheet)
tertiary: interactions between the R-groups of amino acids (positive/negative charges), and interactions between R-groups and the surrounding environment (hydrophobic/hydrophilic), these interactions cause the protein to form a 3-
dimensional shape, becomes functional
quaternary: exists in proteins consisting of two or more polypeptide chains
how can the 3 dimensional (functional) shape of a protein be altered?
alterations in primary structure: from genetic variations through mutations or inherited
denaturation: when heat, pH, or heavy metals disrupt the bonds that hold secondary and tertiary structure together, these agents do not disrupt the peptide bonds so primary structure isnt altered
how are proteins digested?
proteolytic enzymes hydrolyze peptide bonds to split proteins, when proteins enter the stomach gastrin is released which stimulates the release of gastric juice, HCl in gastric juice then denatures the protein and causes it to unfold which exposes the peptide bond for easier digestion
what is zymogen?
zymogens are inactive enzyme precursors
that require a biochemical change to become an active enzyme, because protease enzymes would destroy the tissues that produce and amass these enzymes, they are stored in inactive form called a zymogen
which protease enzymes are needed for digestion?
stomach: pepsinogen ➔ pepsin (active form) when exposed HCl, pepsin hydrolyzes peptide bonds resulting in multiple polypeptide chains
pancreas: trypsinogen ➔ trypsin by enterokinase (brush border enzyme), trypsin then causes chymotrypsinogen ➔ chymotrypsin and procarboxypeptidase ➔ carboxypeptidase
this causes complete hydrolysis of polypeptides into AA and AA is absorbed into enterocytes
where does the amino acid pool come from?
protein turnover and dietary protein
what is the protein requirement based off of?
grams protein/kg of body weight/day (based on growth, maintenance, and repair), key indicator of protein requirements is nitrogen balance (NB)
NB is determined by comparing nitrogen intake (NI) from dietary protein and
nitrogen loss (NL) as urea (urine), indicates whether the body is gaining, losing or maintaining muscle mass
who needs a positive nitrogen balance (NI<NL)?
infants, kids, pregnant women (to support growth), recovery for illness/injury (to replace protein loss), or strength training (to support muscle growth)
what is sarcopenia?
age-related (>50 y) loss of muscle mass and muscle function called sarcopenia, evidence that increased protein intake (1.5 g protein/kg body weight/day) needed to
slow the loss of muscle in older adults
what is deamination?
in the liver when the amine group (NH3) is removed from the CHO carbon backbone, liver converts NH3 to ammonia which is then converted to urea, kidneys then filter urea out of the blood and it is excreted as urine
what is hepatic encephalopathy?
if the liver is diseased and unable to convert ammonia to urea, ammonia accumulates in the blood, may benefit low protein diet until ammonia cleared from
blood, elevated ammonia disrupts brain
function causing confusion, disorientation, memory loss, and possible coma
plant protein vs animals protein?
plant proteins tend to be incomplete
protein sources and animal proteins are
sources of complete proteins
incomplete vs complete proteins?
incomplete: protein lacking or has significantly low amounts of one or more essential amino acids, many incomplete proteins can combine to provide a complete protein source (protein complementation)
complete: protein provides all essential amino acids in required amounts
