Exam 1 Flashcards
During digestion, what is each macronutrient broken down into
carbs, fat, protein
carbs –> simple sugars
protein –> amino acids
fats —> glycerol + fatty acid
5 examples of chemical digestion
- amylase
- lipase
- HCl
- Bile
- Protease
4 stages of digestion
- ingestion
- digestion
- absorption
- excretion
Purpose of mechanical digestion
increase surface area to allow for increased enzymatic activity
Anatomy of the GI tract
- mouth
- esophagus
- stomach
- duodenum (SI)
- jujenum (SI)
- illieum (SI)
- cecum (LI)
- Ascending colon (LI)
- Transverse colon (LI)
- Descending colon (LI)
- Rectum (LI)
Peristalsis
coordinated muscular contractions that propel food through the GI tract
Segmentation
uncoordinated muscular contractions that mix digestible materials for further breakdown
Chemical digestion in the mouth
- amylase
2. lipase
What are the 3 pancreatic secretions and their function
- amylase - carb digestion
- lipase - fat digestion
- Bicarbonate - stabalize pH
Where is bile secreted and what is its purpose
Liver
emulsifies fat
Rugae
folded walls in the stomach, can expand to increase stomach volume
Main site of chemical digestion
small intestine
parietal cells
found in stomach secrete HCl + intrinsic factor (B12 absorbtion)
Chief cells
found in stomach, secrete pepsinogen and lipase
Pepsinogen vs pepsin
Pepsinogen is inactive, becomes active Pepsin when HCl is present. Functions to breakdown protein.
Purpose of the Hepatic Portal System
water soluble nutrients in the SI bypass the circulatory system and go right to the liver. Fat soluble nutrients enter the lymph system.
Define metabolism
the sum of all of the physical and chemical reactions within an organism that are responsible for building up and breaking down molecules
Define energy metabolism
the sum of all the chemical reactions involved in the storage and breaking down of fuels to produce ATP
coenzymes
organic molecules necessary to the function of enzymes
2 ways glucose is stored when it reaches the liver
- glycogen
2. converted to fatty acid and stored as triglycerides in adipose tissue
What are 2 other molecules processed by the liver for energy
- fructose
2. galactose
Inputs and outputs of glycolysis
Input : glucose
Output: 2 pyruvate, 2 NADH, 2 ATP
Wheres does glycolysis occur
cytosol
Explain the Cori Cycle
IN MUSCLES
glucose —-> 2 pyruvate —> 2 lactate + 2 ATP
2 lactate is transported to the liver
IN LIVER
2 lactate —–> 2 pyruvate —–> 2 glucose
costs 6 ATP to accomplish this
How much ATP is produces by anaerobic fermentation
2 ATP
What other function does anaerobic respiration serve other than ATP production
Regenerates NAD+ for use in glycolysis
Input and output of pyruvate oxidation
Input: 2 pyruvate
Output: NADH, CO2, 2 acetyl-coA
How many ATP are produced per round of the citric acid cycle
1 ATP
How many ATP are produced in the citric acid cycle per glucose molecule
2 ATP
How many NADH are produced per round of the citric acid cycle
3 NADH
How many NADH are produced per glucose molecule
6 NADH
How many FADH2 are produced per round of the citric acid cycle
1 FADH2
How many FADH2 are produced per glucose molecule
2 FADH2
3 requirements for the ETC
- copper (enzymes)
- iron (cytochromes)
- oxygen
2 sources of stored fatty acids for energy
- triglycerides in serum lipoprotein (free circulation)
2. triglycerides stored in adipose tissue
2 enzymes that mobilize triglycerides
- Lipoprotein lipase (serum lipoprotein)
2. Hormone sensitive lipase (adipose tissue)
2 stages of fat mobilization
- Lipolysis (Triglycerides —-> fatty acid + glycerol)
2. B oxidation
Carnitine
Used to transport fatty acids from the cytosol to the mitochondria for B oxidation
During fatty acid oxidation, how many carbons are broke apart at a time
2
Where does B oxidation take place
mitochondria
What are fatty acids converted to in B oxidation
Acetyl coA
What is produced during B oxidation of a odd numbered chain and what happens to it
propnyl coA ; it enters as a citric acid cycle intermediate
What are the body’s two preferred energy sources
- carbs
2. fat
What are sources of amino acids for the body
- dietary protein
2. breaking down body proteins
How can amino acids be used to make glucose or fatty acids
The amino group is removed and then the carbon skeleton that remains will make glucose in fasted state or fatty acids in a fed state
What is the precursor molecule(s) for ketone bodies
2 molecules of acetyl coA
3 examples of ketone bodies
- acetone
- B hydroxybuteric acid
- acetoacetic acid
What are the major and minor sites of alcohol metabolism
MAJOR: liver
minor: stomach
Explain how alcohol becomes acetate
Alcohol —alcohol dehydrogenase—> acetaldehyde
acetaldehyde—>acetaldehyde dehydrogenase —> acetate
Explain the MEOS pathway
A method of alcohol oxidation found in the endoplasmic reticulum, it functions when there is excessive alcohol consumption and it prevents the BAC from rising quickly because alcohol is metabolized quicker.
How are the following nutrients stored
- Glucose
- dietary triglycerides
- Dietary proteins
- glycogen in muscle and liver
- adipose tissue
- circulating amino acids
When is gluconeogensis employed and how is it done
Gluconeogensis occurs in a fasted state and uses glucagonic amino acids
Lipogenesis
synthesis of fat from non fat sources
Name 4 things that can be converted to fat through lipogenesis
- alcohol
- acetyl coA
- carbs
- ketogenic amino acids
During a fed state, there is a rise in which hormone
insulin
during a fasting state, there is a rise in which hormone(s)
- glucagon
2. epinephrine
During a prolonged fast (2 days+) which things will bodily processes will increase or decrease
DECREASE
- temp
- energy
- metabolic rate
INCREASE
- fatty acid use
- ketone bodies
What happens to the risk of child obesity when there is starvation early in pregnancy
Increases
What happens to the risk of child obesity when there is starvation late in pregnancy
less risk of obesity
Define nutrition
The study of 1. intake 2. behavior 3. nutrients 4. constituents of nutrients and how they affect overall human health
Differentiate between essential and non-essential nutritents
essential —> body cannot make
nonessential –> body can make
Name the 5 causes of death among the leading causes that are affected by nutrition
- Cancer
- Heart disease
- stroke
- diabetes
- alzheimers
6 essential nurtients
- carbs
- fat
- protein
- minearls
- vitamins
- water
How many calories (Kcal) are associated with 1 gram of each nutrient
Carbs
Fat
Alcohol
Protein
Carbs —-> 4 kcal
Fat —-> 9 kcal
Protein —> 4 kcal
Alcohol —-> 7 kcal
Phytochemicals
Biologically active chemicals in plants, provide them with color, aroma, and flavor
What are some benefits that may be associated with phytochemicals
- anti-inflammatory
- antioxidant
- hormone - like action
What is the leading cause of worldwide blindness
Vitamin A deficiency
DRI values
Dietary Reference Intake
4 values that constitute the amount of a specific nutrient required to meet the dietary needs on 97-97% of the population to keep them healthy.
EAR value
Estimated Average Requirement
The amount of a certain nutrient that a population of a certain age and sex requires to ensure that 50% of that population is healthy
RDA value
Recommended Daily Allowance
The amount of a certain nutrient that a population of a given age and sex needs in order to ensure that 97-97% of that population is healthy
AI value
Adequate intake value
The minimum amount of a nutrient that should be consumed in order to be healthy as determined by both observation and research
UL value
Upper limit
The maximum amount of a certain nutrient that can be consumed without any health consequences
What is the Acceptable Macronutrient distribution range (AMDR) for each macronutrient
Carbs —-> 40-65%
Protein —> 10-35%
Fat —-> 20-35%
Food desert
a specific area or region in which access to affordable and quality foods is impaired
What constitutes an urban area food desert
not within 1 mile of a grocery store
What constitutes an rural area food desert
not within 10 miles of a grocery store
Focuses of MyPlate 2015
- variety
- nutrition
- amount
What should sodium intake be limited to
= 2300 mg for a normal person
= 1500 mg for a HTN/Pre-HTN pt
What should added sugar consumption be limited to
= 10% of total calories
What should trans fat/saturated fat consumption be limited to
= 10% of total calories
4 characteristics of a healthy diet
- balance
- variety
- moderation
- adequecy
Nutrient content claims
describes the level of nutrients in something
“good source of fiber”
Health claims
links food w/ incidence of a disease
“May reduce risk of heart disease”
ARE FDA regulated
Structure/function claim
Describes a nutrient role in health
“heart healthy”
NOT FDA regulated
Celiac’s Disease
Body mounts an immune response against gluten and in doing so will damage the vili in the small intestine leading to chronic malabsorption.
How much ATP is produced from 1 NADH
2.5
How much ATP is produced from 1 FADH2
1.5
