Lecture 21 Flashcards
- ________: the process of providing or obtaining the food necessary for health and growth
- digestion: it is a _______ process that breaks down large food molecules to ________
- nutrition
- catabolic; monomers
Digestion:
building blocks (monomers) of…
- carbohydrate=
- proteins=
- lipids=
- nucleic acids=
- monosaccharide
- amino acids
- fatty acid + glycerol
- nucleotide
- _________: the process of moving substance from the lumen of the gut into the body
- Metabolism: the sum of all ________ _________ in the body
1. __________: all reactions that BUILD larger molecules or structure from smaller ones–> _______ energy
- __________: all processes that BREAK down complex structures to simpler ones -> __________ energy
- absorption
- biochemical reactions
1. Anabolism; requires
2. Catabolism; releases
- _________: a substance in food the body uses to promote normal growth, maintenance, and repair
- ____________: those that are inadequately synthesized by body cells and must be INGESTED in the diet
- nutrients
- essential nutrients
6 Major Nutrient Categories
1.
2.
3.
4.
5.
6.
- Carbs
- Protein
- Fats
- Water
- Vitamins
- Minerals
- ____nutrients: must be consumed in relatively large quantities
-supply ______ and are used as building blocks
1.
2.
3. - ____nutrients: only small quantities are required
-play role in various physiological processes, but they do not provide energy directly
1.
2.
- MACRO
-energy
1. Carbs
2. Proteins
3. Fats - MICRO
1. Vitamins
2. Minerals
- ___________: it indicates the proportion of total daily calories that come from a specific nutrient
- How much of your daily caloric intake should be deducted to…
- Carbohydrates=
- Proteins=
- Fats=
- Saturated fats=
- percent (%) of daily caloric intake
- 45-65%
- 10-35%
- 20-35%
- ≤ 10%
1 _______(__) is the amount of heat (energy) needed to raise the temperature of ____ gram of water by ____ °C
calorie (c); 1; 1
__________ calories (c) = 1 ________ (___) = 1 __________(_____
- ________(__)= on food labels
- _________(___)= in biochemistry and physiology
1000; Calorie (C); kilocalorie (kcal)
- Calorie (C)
- kilocalorie (kcal)
In the realm of food…
- Calories are units representing the ability of _____ to be converted by the body into _______
- FOOD; energy
Three nutrients that provide energy:
1.
2.
3.
- they are measured by the _________
- This measurement represents the amount of _______ released when they undergo metabolic processes in the body
- Carbs
- Proteins
- Fats
- calories
- energy
How many calories are produced when one gram of….. are fully oxidizes in our body?
- Carbohydrates=
- Proteins=
- Fats=
- 4 kcal/g
- 4 kcal/g
- 9 kcal/g
__________ are calories that contribute to your total caloric intake but supply little or no nutritional value
- e.g. _____ (7.1 kcal/g) and _________ promote malnutrition; they _______ the appetite but fail to provide other nutrients
empty calories
- alcohol; sugary foods; suppress
Types of water soluble vitamins
1
2
Types of lipid soluble vitamins
1
2
3
4
- which to the two vitamin groups, has a higher risk of accumulating in your body until reaching toxic levels?
- Vitamin B
- Vitamin C
______________ - Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
- fat soluble vitamins; because they are stored in the body (dissolved in fat and can accumulate)
Water soluble vitamins are not accumulated in the body in large amounts because…
excess amounts are readily excreted though urine
Vitamin B12 requires ______________ to be absorbed in the intestines
- secreted by ______ cells in the stomach
intrinsic factor
- parietal
Most iron in our diet is in the ________ form (Fe3+)
A. to be absorbed, it must be in the ______ (Fe2+) form or bound by heme
B. This form can be achieved in the ________ by low pH of gastric acid which weakens ______ iron has with other food molecules and by the enzyme ______________
C. Which transporter does iron use to enter inside the enterocyte? ______________
- ferric
A. ferrous
B. duodenum; bonds; ferric reductase
C. Divalent Metal Cation Transporter 1 (DMT 1)
_________: transports iron out of cells and into the bloodstream
- primarily found on the surface of _________ in the small intestine and __________ in the reticuloendothelial system
ferroportin
- enterocytes; macrophages
__________ is a protein responsible for transporting iron in the bloodstream
- it binds to iron and carries it throughout the body, delivering it to cells that need it for various functions, including
- ___________ synthesis in red bone marrow
- ____________ synthesis in the muscle
transferrin
- hemoglobin
- myoglobin
________ RBCs are phagocytized by ____ ____________, releasing iron from hemoglobin through ________ and back into the bloodstream for transport to other tissues and organs via the protein ___________
senescent; RES macrophages; ferroportin; transferrin
____________ is a protein found in cells (mostly in _____ and _________) that serves as the primary intracellular ______ form of iron in the body
Ferritin; liver; macrophages; storage
- iron is stored in cells primarily through binding to the protein ________
- the _______ is the organ that represents the primary storage site of iron
- ferritin
- liver
- ___________ is a peptide hormone produced by the ______ that regulates iron absorption and mobilization
- main objective is to _______ levels of iron in the blood
- hepcidin; liver
- DECREASE
Hepcidin decreases blood levels of iron by….
1. inhibiting the iron absorption from the ________
2. inhibiting the iron _______ from ______ RBCs
3. inhibiting the iron release from _________ and _________
- hepcidin achieves this goal by binding to ______________ which triggers internalization and degradation of this, therefore _______ the export of iron from cells into the bloodstream
- intestine (enterocyte)
- recycling; senescent
- hepatocytes; macrophages
- ferroportin; reducing
If blood iron levels increase… this would result in an _________ of hepcidin production by the liver
INCREASE
- bc hepcidin acts as a negative regulator of iron absorption and release
An increase in RBCs would result a _____________ in hepcidin production by the liver
decrease (we iron availability in order to produce hemoglobin for those new RBCs)
- Two primary organs of carbohydrate digestion=
1.
2. - carbohydrate digestion begins in the ________ with the action of ____________
- Mouth (oral cavity)
- Small intestine
- mouth; salivary amylase
- ____________ a complex carbohydrate molecules composed of multiple sugar units bonded together
- _________ _________ is found in saliva and is responsible for breaking down these
- polysaccharides
- salivary amylase
Carbohydrate digestion does _____ continue in the stomach even though the bolus from your mouth contains some salivary amylase because the ____ pH in the stomach ________ it
NOT; low (acidic); inactivates
The amylase in your small intestine is primarily secreted by the ________
pancreas
Two brush border enzymes that act on olgiosaccharides composed of more than ___ simple sugars
1.
2.
THREE
1. Dextrinase
2. Glucoamylase
___________: enzymes responsible for breaking down disaccharides (double sugar molecules) into ___________, which are single sugar molecules
3 types:
1.
2.
3.
- primarily found in the microvilli (__________ membrane) of the epithelial cells lining the ______________
disaccharidases;monosaccharides
1. Maltase
2. Sucrase
3. Lactase
- brush border; small intestine
Absorption of monosaccharides occurs only in the ______________ which they get absorbed into the __________
small intestine; bloodstream
The primary function of cellular respiration is to generate _____, which serves as the main ________ currency of the cell, by breaking down ________ and other organic molecules in the presence of _________
ATP; energy; glucose; oxygen
Equation representing the process of AEROBIC glucose respiration:
Glucose (C6H12O6) + 6 Oxygen (6O2) —> 6 Carbon Dioxide (6CO2) + 6 Water (H2O) + Energy (in the form of ATP)
For each glucose molecule ___________ to carbon dioxide and water, there is a net gain ____ ATP
oxidized; 32
Three consecutive pathways of glucose aerobic respiration
1.
2.
3.
- Glycolysis
- Citric Acid Cycle (Krebs cycle)
- Electron Transport Chain
ATP is ______ a storage molecule for chemical energy; that is the job of ____________ and _____; When energy is needed by the cell, it is converted from storage molecules into ______
NOT; carbohydrates and fats; ATP
In glucose oxidation, NADH and FADH2 serve as _________ that accept and carry high-energy ________ during the process of cellular respiration. They transfer these _________ to the ___________, where they participate in generating a ____________ gradient that drives ______ synthesis
coenzymes; electrons; electrons; electron transport chain; proton; ATP
Staring and end products of GLYCOLYSIS
- starting=
- end=
- Glucose (six-carbon sugar molecule)
- 2 pyruvate molecules
- ____ pyruvate are obtained per molecule of glucose being oxidized in glycolysis
- in ABSENCE of oxygen, the pathway that pyruvic acid enters is _____________
- In the PRESENCE of oxygen, pyruvate enters the __________ where it undergoes further oxidation in the presence of oxygen. This process involves the conversion of private to __________, which enters the ____________ (aka _________)
- 2
- anaerobic fermentation
- mitochondria; acetyl CoA; citric acid cycle (Krebs cycle)
Pyruvate converts into _________ in order to enter the citric acid cycle (aka _________)
Acetyl CoA; Krebs cycle
In the Citric Acid Cycle
- Acetyl-CoA is oxidized to produce ________,_______,_______, and ______ in the _______________
- It involves a series of enzymatic reactions that result in the complete oxidation of acetyl-coa derived from _______ (from glucose) and other fuel molecules
- carbon dioxide; NADH; FADH2; ATP; mitochondrial matrix
- pyruvate
- What is the final pathway to produce ATP in glucose metabolism? __________ and __________
- What ion gradient is used to make ATP? _______ gradient, created across the ______ mitochondrial membrane during electron transport chain reactions
- electron transport; oxidative phosphorylation
- proton; inner
_________ is a metabolic pathway that occurs in the ________ of almost all cells and involves the break down of ________ into ___ pyruvates
Glycolysis; cytoplasm; glucose; 2
- _____________: making NEW glucose from noncarbohydrate sources (such as aa, lactate, glycerol)
-takes place mostly in the ______ & ______
-occurs under conditions when blood sugar levels are _____, such as during _______, ________, low _____ diets, and ________
- gluconeogenesis; liver; kidneys
- LOW; fasting; starvation; carb; intense
- ______________: process by which glucose molecules are polymerized and stored as glycogen in _____ and _____ cells
-this process occurs when blood glucose levels are ______, typically after a meal
- glycogenesis; liver; muscle
- HIGH
- ___________: the breakdown of glycogen into glucose molecules
-this process occurs when blood glucose levels are ______ and the body requires additional glucose to meet its energy needs
- glycogenolysis
-LOW
Enzymes that act on proteins= _________ or _______
- ________ is the enzyme that imitates the digestion of proteins located in the _______
peptidases; proteases
- Pepsin; stomach
Three brush border enzymes responsible for protein digestion
1.
2.
3.
- Carboxypeptidase
- Aminopeptidase
- Dipeptidase
Dipeptidase in the brush border of eptihlial cells in the small intestine…
split dipeptides into separate AAs
____________: action of brush border enzymes, final stages of digestion occurs when the luminal contents come into contact with the epithelial cells lining the intestine
contact digestion
- Brush border enzymes are located on the _________ of the enterocytes (embedded in the ________ ________ )
- microvilli; plasma membrane
- nitrogen balance: state in which rate of N _______= rate of N ____________
- __________ are our chief dietary source of nitrogen
- ingestion; excretion
- proteins
- __________ nitrogen balance occurs when the intake of nitrogen exceeds the excretion
- _________ nitrogen balance occurs when the excretion of nitrogen exceeds intake
- positive
- negative
Negative nitrogen balance indicates:
- _________ dietary protein intake
- ________ protein breakdown (sic as during prolonged ______ or certain medical conditions)
- _________ loss of nitrogen through urine
- tends to be associated with ______ ______ (muscle proteins are more easily broken down than others)
- inadequate
- increased; fasting
- increased
- muscle atrophy
Positive nitrogen balance indicates:
- ________ retaining of nitrogen than It is excreting
- associated with periods of ________, recovery from _______ or _____, and ________
- MORE
- growth; illness; injury; pregnancy (we need additional protein for tissue synthesis or muscle growth/organ development)
Three stages involved in the amino acid catabolic pathway for ENERGY
1.
2.
3.
- Transamination
- Oxidative deamination
- Keto-acid modification
- the body gets rid of the amino group of the amino acids by transferring it to ___________
- this reaction name is ______________
- alpa-ketoglutaric acid
- transamination
Urea is produced in the body through the ______________ stage
- the amino group of _________ acid is removed as ________ and combined with ____ to form urea during the urea cycle
oxidative deamination
- glutamic; ammonia; CO2
During keto acid modification step
- after the _____ group is removed, the remainder of the molecule is called a alpha-______ acid
- the _____ acid may be converted to _______, ________ or intermediates of the ________________
- amino (NH2); keto
- keto; pyruvate; acetyl-CoA; citric acid cycle
Is it possible to derive energy from proteins? _____
- the goal of ___________ stage is to enable AAs to contribute to _______ production and ________ pathways beyond protein synthesis
YES
- keto acid modification; energy; metabolic
- name of this function group: -NH2= _________
- transamination is the _____ step in using AA as fuel to deaminate them (= remove _____ ______)
- amino group
- FIRST; amino group
Which AA is involved int he transamination reactions that transfer amino group between amino acids and keto acids? __________
glutamte
