Postlab quiz 8 Flashcards
Digestion involves this
breaking down food products so they can be absorbed by the body and be utilized to build and repair our own body systems
The digestive system consists of this tube
alumentary canal
The alumentray canal begins here and ends here
mouth
anus
T/F: the contents of the alumentary canal is considered inside the body
F
Three salivary glands
parotid gland
sublingual gland
submandibular gland
This is the largest organ in the body and is considered a gland
liver
Two functions of the pancreas
exocrine
endocrine
The exocrine function of the pancreas is associated with this
digestion
The endocrine function of the pancrease is associated with this
regulation of blood sugar levels
Abdominal glands of the digestive tract
liver
pancreas
The role of the oral cavity
use teeth, tongue, and salvary secretions to masticate food, and prepare it for swallowing
Pathway of swallowed food
Pharynx esophagus stomach small intestine large intestin anus
most digestive activity takes place here
small intestine
This prepares the food/wastes for defecation
large intestine
Enzymes in the digestive tract do this
assist in all the reactions that reduce molecues to the smallest size so they can be absorbed
Enzymes are this type of molecule
protein
The active sites on an enzyme have this
specificity
Formula associated with enzyme slide
A+B (reactant substrates)—>(enzyme)—->C+D (products)
T/F: Enzymes have a specific optimal temperature
T, a certain temperature will be the best for enzyme activity (remember slide)
These have an effect on enzyme activity
Temperature
pH
substrate concentration
Pepsin is formed here and has this optimal pH
stomach
2 (acidic)
salivary amylase is formed here and has this optimal pH
oral cavity
7 (neutral)
trypsin is formed here and has this optimal pH
small intestine
9 (basic)
T/F: Enzymes only work in one pH environment
F
Explain reaction rate vs substrate concentration when an enzyme is present
Reaction rate increases slowly until a saturation point which becomes the maximum rate of reaction given a set number of enzymes
Gentle uphill slope that flattens out.
Structures in the digestive canal speed digestion by doing this
increasing surface area
Structures of the small intestine that increase surface area
Plicae circularis
villi
microvilli
In the stomach this increases surface area
gastric rugae
The villi of the small intestine are covered in this
brush boarder
Enzymes are imbedded here in the small intestine
Microvilli
Peristalsis does this
Through coordinated muscle movements or peristaltic waves, food is moved through the alumentary canal
Peristaltic waves consists of contractions of these types of muscles
circular
This is moved by peristaltic waves
bolus
Food is moved before, or after the peristaltic wave
before, or in front of
Three enzymes we will look at in lab
amylase
pepsinogen (pepsin)
lipase
Secreded from, substrate, optimal pH, and products: Amylase (ptyalin)
Pancrease,
salivary glands
startch
6.8 maltose and dextrin
Secreded from, substrate, optimal pH, and products: Pepsinogen (pepsin)
chief cells
protein
1.6-2.4
shorter polypeptides
Secreded from, substrate, optimal pH, and products: Lipase
pancreas
triglycerides
8.0
fatty acids and monoglycerides
Maltose is this type of molecule
two-chain sugar
The gastric gland of the stomach consists of these parts (bottom to top)
Chief cell
parietal cell
mucous cell
Two layers of the stomach
mucosa
submucosa
Parietal cells secrete this
HCl
intrinsic factor
This occurs if the mucous layer of the stomach is compromised
ulcer formation
This is the only critical secretion of the stomach, and does this
intrinsic factor
protects Vit. B12 from being digested
Vit. B12 is responsible for this
maturation of red blood cells
Condition that occurs when B12 is not absorbed
peinecious anemia
Enzyme pathway of the stomach
pepsinogen is converted to pepsin in the presence of HCl
Pepsin interacts with ingested proteins and breaks them down into short peptides
Secretions into the small intestine come from these organs
liver
pancreas
Main role of the liver is this
secreting bile salts that emulsify fat
The pancreas secretes these, what do the various secretions do
Pancreatic lipase, breaks down emulsified fat
Pancreatic colipase, assits in breakdown of fat
Trypsin, breaks down protein
Pancreatic amylase, breaks down starch to glucose
sodium bicarbonate, raises pH to about 7.8
Within the villi of the SI there are two types of vessels, what are they
Capillaries
lacteal
These are absorbed into the capillaries of the SI
simple sugars and amino acids
The lacteal is responsible for this
absorbing fats
Pathway of lymph from SI villi to main lymph system
lacteal
lymph vessel
thoracic duct
Step 1: fat digestion in the SI
emulsification of fat droplets by bile salts secreted from the liver/gallbladder through the bile duct
Step 2: fat digestion in the SI
Hydrolysis of triglycerides in emulsified fat droplets into fatty acids and monoglycerides by lipase
Step 3: fat digestion in the SI
Dissolving of fatty acids and monoglycerides into micelles to produce “mixed micelles”
Absorption of fat in the SI: pathway
Fatty acids and monoglycerides enter the epithelius villi.
Reconstitution of the FA and MG into triglycerides inside the cell.
Apoprotein attaches to triglyceride to cause formation of chylomicrons.
Chylomicrons are exocytosed into the lacteal.
What protein will we be testing in lab
egg white, and the effects of pepsin on it
Another name for Amylase
ptyalin
Two types of coordinated muscle contractions in the GI tract
peristalsis
segmentation
The movement of digested materials across the mucosa of the digestive tract into the blood-stream occurs through this
absorption
What tests did we use to examine amylase (ptyalin) digestion on starch
Benedict’s test
Lugol’s (iodine) solution
Benedict’s test, tests for this
maltose formation
Lugol’s (iodine) solution tests for this
starch
What is used to test for the presence of musin in saliva
When mixed with a 1% acetic acid solution a precipitate will form indication the presence of music
what type of molecule is mucin
glycoprotein
List the rating system for lugol’s solution, and what is it testing for
presence of starch (lack of breakdown)
Reddish brown (less amount of starch) to dark purple (no starch digestion)
(+++), (++), (+), (-)
Most to least digestion
List the rating system for Benedict’s test, and what is it testing for
presence of maltose (breakdown of starch) (+++) = red (++) = orange-yellow (+) = green (-) = blue Red = most starch converted to maltose Blue = maltose has not been found
Function of HCl in the stomach
activates pepsin
produces stomach pH of about 2
denaturation of proteins
Infection of this or overuse of these can lead to peptic ulcers
helicobacter pylori
NSAIDs (nonsteroidal anti-inflammatory drugs)
Grading scale for protein diegestion
(+++) = most digestion
++), (+), (-
Why is pancreatic lipase ineffective by itself
it is a water soluble enzyme trying to act on large lipid droplets
What helps pancreatic lipase breakdown lipids
bile salts
Bile salts are this type of molecule
amphipathic
This is needed to displace the bile salts to allow lipase activity within the bile salt coating
pancreatic colipase
This is produced when dairy fat is digested
butyric acid
Butyric acid is most easily recognized by this
rancid odor
Fat digestion produces this
acid
This color will show if digestion of fat takes place
pink
this color will show if no fat digestion takes place
blue
Trypsin does this and is found here
small intestine
breaks-down protein into shorter polypeptides
Enzyme definition
biological catalyst, not changed during use
Active site has substrate specificity
Review graphs/diagrams from class
…
Lipids go from this to these in the presence of lypase
triglycerides
2 Fatty acids, 1 monoglyceride
What is lactose intolerance
deficiency in the enzyme lactase which is responsible for the hydrolysis of the disaccharide lactose into glucose and galactose
This happens to lactose in the GI tract of someone who is lactose intolerant
lactose cannot be absorbed as a disaccharide and will remain undigested and unabsorbed through the digestive tract
Lactase deficiency generally develops in one of these three ways
Primary
secondary
congenital
Lactase deficiency: primary
normal decline in lactase production that comes with age
Lactase deficiency: secondary
result of injury or illness, for example:
crohn’s disease
celiac disease
or after surgery
Lactase deficiency: congenital
the most rare form, infants can be born with a complete lack of lactase
This can effect the sevarity of the symptoms of lactose intolerance
how much lactase the body makes
Signs and symptoms of lactose intolerance
Bloating
pain or cramps in the lower belly
gurgling or rumbling sounds in the lower belly
gas
loose stools or diarrhea (sometimes foamy)
throwing up
Symptoms usually begin within this time frame after eating this
30 min - 2 hours
eating or drinking milk or milk products
Treatment for lactose intolerance
no cure
controling symptoms is up to the individual
Limit dairy consumption
eat/drink dairy with other foods
Take products that help individuals digest lactose
Supplement calcium from other sources
product to help individuals digest lactose
Lactaid
Dairy product that is generally easier to digest
yogurt
Prognosis for lactose intolerance
Normal life if dairy intake is limited
many can also eat dairy symptom free with the use of medications/products
Two types of metabolic reactions
anabolism (endergonic)
catabolism (exergonic)
anabolism =
synthesis of larger molecules from smaller molecules
requires energy
endergonic
catabolism
breakdown of larger molecules into smaller molecules
releases energy
exergonic
Energy is gained form, and stored in this form
ATP
Adenosine triphospate
Two types of cellular respiration
anaerobic respiration (does not require oxygen) aerobic respiration (requires oxygen)
Another word for anaerobic respiration
glycolysis
T/F: aerobic respiration is considered the primitive type of respiration
F, anaerobic
Formula for glycolysis
glucose -> 2 pyruvic acid + electron carriers
In aerobic respiration pyruvic acid is converted into (full pathway)
acetyl CoA -> citric acid + electron carriers
Citric acid enters into this cycle
krebs cycle
All electron carriers enter this chain
electron transport chain
This combines with acetyl CoA to from this in the krebs cycle
Oxaloacetic acid
citric acid
These are formed during the krebs cycle (energy)
3 NADH
1 ATP
1 FADH2
In the electron transport chain these are pumped into this space
hydrogen ions
intermembrane space
This is needed to activate the hydrogen pumps
electron carriers
These are imbedded in the inner membrane of the mitochondria and assist in the electron transport chain
enzyme systems
As electrons move from one enzyme system to the next this occurs
hydrogen ions are pumped into the intermembrane space
These two things are used to produce ATP in the electron transport chain
High H+ concentration
ATP Synthase
(ADP + Pi = ATP)
This much ATP is produced through aerobic respiration
30
This many ATP are produce by the krebs cycle and glycolysis
4
This many ATP are produce by the electron transport chain
26
Acetyl CoA can be converted into this four things
Citric acid (krebs cycle)
fatty acids
ketone bodies
cholesterol
Energy source preference: brain
glucose
Energy source preference: skeletal muscles (resting)
Fatty acids
Energy source preference: liver
fatty acids
Energy source preference: Heart
fatty acids
Insulin facilitates this
uptake of glucose into cells from the blood
Insulin increase does this
reduces blood sugar levels
increases uptake of glucose into cells
Two types of cells in the pancreatic islets
alpha cells
beta cells
Beta cells produce this
insulin
alpha cells produce this
glucagon
Insulin surge happens at this time
just after eating
Starving in terms of physiology occurs at this time
approx 4 hours after eating
Glucagon surge happens at this time
starvation
When blood glucose levels go down this occurs
alpha cells secrete more glucagon (reduced insulin secretion)
reduces cellualar uptake of glucose
increases glycogenolysis and gluconeogenesis
blood glucose levels increase
glycogenolysis
glycogen is broken down and glucose is released into the blood
gluconeogenesis
conversion of non-carbohydrates into glucose
Both insulin and glucagon have this effect on blood glucose
negative
How is insulin secreted
Stimulus: increase in blood glucose GLUT2 receptor (on beta cell) allows glucose into the cell Leads to insulin being released into the blood
You are considered diabetic if you have a blood glucose level above this about 2 hours after eating
200 mg/dl
Review blood glucose/ plasma insulin slide from the podcast
…
When plasma insulin levels do not increase after a meal the person is said to have this type of diabetes
Type 1
Metabolism as he relates to glucose after absorption of a meal
Glucose (+)
Insulin (+), glucagon (-)
Insulin/glucagon ratio (+)
anabolic formation of glycogen, fat, and protein
Blood glucose, amino acids, fatty acids, and ketone bodies (-)
Metabolism as it relates to glucose after fasting
glucose (-) insulin (-) glucagon (+) insulin/glucagon ratio (-) catabolic hydrolysis of glycogen, fat, and protein + gluconeogenesis and ketogenesis Blood glucose, amino acids fatty acids, and ketone bodies (+)
Type 1 diabetes is caused by the reduction of this, is this type of disease
beta cells
auto-immune
type 1 diabetes: age of onset, development of symptoms, percent of diabetic population, development of ketoacidosis, associating with obesity, beta cells of islets, insulin secretion, autoantibodies to islet cells, associated with particular MHC antigens, treatment
under 20 rapid about 10% common rare destroyed decreased present yes insulin injections
Type 2 diabetes: age of onset, development of symptoms, percent of diabetic population, development of ketoacidosis, associating with obesity, beta cells of islets, insulin secretion, autoantibodies to islet cells, associated with particular MHC antigens, treatment
over 40 slow about 90% rare common not destroyed normal or increased absent unclear diet and exerciser: oral stimulators of insulin sensitivity
Review glucose and insulin graphs towards end of post cast
…
the most severe type 2 diabetics may need this
insulin
What do me measure to determine the resting metabolic rate of a human (indirect)
O2 consumption
