Ch. 27 Nutrition and Metabolism Flashcards
Define nutrition and list the types of nutrients
def: nutrients contained in foods eaten
Types: carbohydrates, lipids, proteins, vitamins, and minerals
Define metabolism and list its 2 processes
def: food usage in cells, involves chemical reaction and enzymes
Processes: catabolism and anabolism
Discuss catabolism and the 2 kinds of energy released in catabolism
Catabolism-decomposition of nutrients in cells
1. Heat energy- not useful for cell work so released into blood, maintains body/blood temp
2. chemical energy-ATP- useful energy, but before can be used must be stored in ATP
Synthesis of nutrients in cells, requires energy (from ATP)
Disucss the ATP/ADP system and how it relates to catabolism and anabolism
a. chemical energy (from catabolism) used to build ATP
b. when ATP breaks down-> chemical energy used in anabolism (or other cell work)
c. ATP/ADP System links catabolism to anabolism
Discuss metbolism differences in cells
a. Rate differences- more active cells have faster metabolism (catabolism)
b. Product differnces- all cells dont build the same products in anabolism
Explain why carbohydrate metabolism really means glucose metabolism.
because carbs are a form of glucose and when they are digested they become glucose
discuss a basic principle regarding carbohydrates and lipids with respect to catabolism and anabolism
Carbohydrates and lipids; catabolism primary; anabolism secondary (energy foods); carbohydrates preferred-> means carbohydrates catabolized, lipids stored (reverse energy)
discuss the 2 events that prepare glucose for metabolism
1. Glucose transport (into cells)-requires insulin
2. Glucose phosphorylation
a. END PRODUCT:Glucose 6 phosphate (G-6-P)
summary: glucose-> G-6-P
b. IRREVERSIBLE MOST CELLS (EXCEPTION:LIVER)
List the 3 process involved in the usual catabolism of glucose
2. citric acid cycle
3. electron transport system
Define gycolysis, summarize the metabolic pathway of glycolysis and duscyss serveral generalizations concerning glycolysis.
Summary: G-6-P--->2 pyruvic acids+ E (heat and Chemical, 2 ATP)
1) Occurs in Cytoplasm
2) Involves a Metabolic Pathway
4) Has Low Energy Yield
Summarize the metbolic pathway of he citric acid cycle and the electron transport system, discuss serval generalizations about both processes, define and discuss the importance of oxidative phosphorylation.
Summary for both processes:
2 pyruvic acids+6 O2----> 6 CO2+ 6 H20+ E(Heat and chemical, 36 ATP)
‑ Generalizations About Both Processes:
1) Both Occur in Mitochondria
2) Each Involves a Metabolic Pathway
4) Has High Energy Yield
‑ Oxidative Phosphorylation:
1) Forms ATP in the Presence of Oxygen
2) Occurs During Processes 2 and 3
Summarize the aerobic pathway of glucose catabolism(aerboic respiration)
Glucose + 6 O2 ‑‑‑> 6 CO2 + 6 H2O + E (Heat and Chemical, 38 ATP)
Discuss the anarobic pathway of glucose catabolism (anaerobuc respiration(, including definition, when this process occurs, what metabloic pathways are used, why it can sustain cells for short periods only, and the importance of anaerobic pathway.
‑ Glucose Catabolism in the Absence of Oxygen
‑ Cells Revert to This Pathway When O2 is Lacking
‑ Uses Glycolysis and Lactic Acid Fermentation
‑ Can Sustain Cells For Only Short Periods of Time
(Low Energy Yield)
Disucss the anabolism of glucose (glycogenesis)
‑ Building Glycogen
‑ Occurs When Cells Energy Needs Are Being Met and Extra Glucose Remains in the Blood (Blood Glucose Approx.100mg/100ml Blood)
‑ Occurs in Most Cells (Not Brain), Especially Liver and Muscle
‑ Splitting Glycogen
‑ Occurs When Blood Glucose Decreases (Approx. 70mg/100ml Blood)
‑ End Products:
1) Most Cells: G‑6‑P (Enters Glycolysis)
2) Liver Cells: Glucose (Enters Blood)
‑ Beginning of "New Glucose"
‑ Occurs in Liver Cells When Blood Glucose Levels Are Dangerously Low (60mg/100ml Blood) and Glycogen Stores Are Exhausted
Explain 2 reasons hwy the liver plays a vital role in maintaining the homeostasis of blood glucose.
1) Liver Can Reverse Glucose Phosphorylation
2) Liver Can Carry Out Gluconeogenesis
List 2 groups of hormones that control glucose metabolism
Hypoglycemic hormones and hyperglycemic hormones
List the 2 hypoglycemic hormones and explain what each does to decrease blood glucose. What is the role of TSH?
‑ Assists Glucose into Cells
‑ Stimulates Glucose Metabolism
b.TSH AND THYROID HORMONE
‑ Thyroid Hormone Regulates Metabolism (Glucose Catab)
List the 4 hyperglycemic hormones and explain what each does to increase blood glucose. what is the role of ACTH?
‑ Stimulates Liver Glycogenolysis Primarily
(Also Stimulates Gluconeogenesis)
‑ Stimulates Liver and Muscle Glycogenolysis
c. ACTH AND GLUCOCORTICORDS
‑ Glucocorticords Stimulate Gluconeogenesis
‑ Also, Glucocorticords Stimulate Fat Catabolism and Decrease Glucose Catabolism (Relates to Gluconeogenesis)
d. GROWTH HORMONE
‑ Stimulates Fat Catabolism and Decreases Carbohydrate Catabolism
Discuss the mechaism involved in the catabolism of lipids
‑ Glycerol Catabolized Using Glycolysis, Citric Acid Cycle, and the Electron Transport System
‑ Fatty Acids Undergo Beta Oxidation then Catabolized Using the Citric Acid Cycle and the Electron Transport System
*NOTE: Final Metabolic Pathways of Lipid Catabolism are the Same as the Metabolic Pathways of Glucose Catabolism (Lipid Catabolism Yields More Energy Than Carbohydrate Catabolism)
Define ketogenesisand discuss when and where this process occurs as welll as the dangers of ketogenesis.
‑ Formation of Ketones
‑ Occurs in Liver Cells When the Rate of Fat Catabolism is Increased (i.e., Starvation, Diabetes Mellitus,Excessive GH or Glucocorticords)
‑ Ketones Sent to Other Cells to be Catabolized
‑ Dangers: If Excessive, Ketones Accumulate in the Blood Creates Acidosis and Coma
Discuss the anabolism of lipids (lipogenesis), including how this process occurs. Explain how stroage of lipids (triglycerides) and stroage of glycogen differs.
ANABOLISM ‑ LIPOGENESIS
‑ Lipogenesis = Formation of Lipids
‑ Triglycerides Anabolized from Glycerol and Fatty Acids,AS WELL AS FROM EXCESS GLUCOSE OR AMINO ACIDS!
‑ Adipose Cells Can Store A Limitless Amount of Triglycerides (Reserve Energy) Compared to Liver and Muscle That Can Store Only a Limited Supply of Glycogen
Discuss the control of lipid metabolism and how the control of lipid metabolism is related to the control of glucose metabolism
‑ Lipid Metabolism is Inversely Related to Glucose Metabolism
1.INSULIN: Increases Glucose Catab., so Decreases Fat Catab.
2.GROWTH HORMONE: Increases Fat Catab.
3.ACTH AND GLUCOCORTICORDS: Increases Fat Catab.
Disucss a basic principle realted to protein metabolism
* Proteins: Anabolism Primary, Catabolism Secondary(Building Foods)
Discuss protein anabolism (protein synthesis)
‑ AKA Protein Synthesis
‑ Involves Ribosomes
‑ Processes: Transcription and Translation
‑ Builds Proteins (Structural/Functional) from Amino Acids
‑ Cell's Genes Determine Which Proteins the Cell Will Build
Discuss the catabolism of proteins
‑ Occurs in Liver Cells; Amino Acids Undergo Deamination ‑‑‑> Ammonia and Ketoacids
‑ Ammonia Converted to Urea, Urea Excreted in the Urine
‑ One of 3 Things Can Happen to the Ketoacid
(Depends Upon Cells Needs)
1) Can be Converted to Glucose (Gluconeogenesis)
2) Can be Converted to Fat (Lipogenesis)
3) Can be Catabolized in the Citric Acid Cycle, Electron Transport System
*NOTE: The Citric Acid Cycle and Electron Transport System Play Central Roles in the Catabolism of All Nutrients
Define portein balance adn when protein balance occurs. Why is protein balance also known as nitrogen balance?
PROTEIN (NITROGEN) BALANCE
‑ Should Exist in the Normal, Healthy Adult
‑ Protein Anabolism = Protein Catabolism (or Protein Intake (in Foods) = Protein Lost (in Urine, Feces, Sweat))
List 2 kinds of protein (nitgroen) imbalance.
negative and postive nitrogen balance
Define negative nitrogen balance and tell when it would occur.
NEGATIVE NITROGEN BALANCE
‑ Protein Catabolism > Protein Anabolism
(or Protein Lost from Body > Protein Intake)
‑ Examples: Protein Poor Diet, Starvation, Illness
with Tissue Wasting)
Define postive nitrogen balance and tell when it would occur.
‑ Protein Anabolism > Protein Catabolism
(or Protein Intake > Protein Lost From Body)
‑ Examples: Growth, Pregnancy
List the 2 groups of hormones that control protein metabolism.
protein anabolic hormones and portien catabolic hormones
Define portein anabolic hormone and list 2 hormones that are protien anabolic.
PROTEIN ANABOLIC HORMONES‑ Stimulate Protein Anabolism
Define protein catabolic hormone and list 1 protein catabolic as well as why it is protein catabolic. What is the role of ACTH?
PROTEIN CATABOLIC HORMONES: ACTH AND GLUCOCORTICORDS
‑ Stimulate Protein Catabolism (B/C Stimulate Gluconeogenesis)
Define vitamins and minerals and explain the major funciton of both. list some additional functions of Ca, P, Fe.
‑ Vitamins: Organic/Minerals (Electrolytes): Inorganic
‑ Major Function of Both is to Help Enzymes Function Properly
‑ Vitamins & Minerals Have Additional Functions
‑ Examples: Ca, P ‑ Bone Formation, Ca ‑ Muscle Contraction,Fe ‑ Hemoglobin Formation, Etc.
Define metabolic rates and dicuss how metabolic rates are expressed.
DEFINITION‑ Rate of Catabolism (Energy Release) in a Given Time
‑ Kilocalories (kcals) (Commonly Known as Calories)
‑ Energy Unit
List the 2 kinds of metabolic rates
Basal Metabolic Rate(BMR) and Total metabloic rate(TMR)
Dicuss Basal Metabolic Rate (BMR).
BASAL METABOLIC RATE (BMR)‑ Rate of Catabolism Under Basal Conditions
‑ Individual is: a) Awake But Resting, b) Postabsorptive(12‑18 Hours), c) in a Comfortably Warm Environment
‑ Basal Conditions are Used to Create a Standard That Can ThenBe Used For Comparison
3. FACTORS INFLUENCING
a. SIZE‑ The Larger the Person, the Higher the BMR (Relates to BSA)
b.SEX‑ BMR is Higher in Males Than in Females (5‑7%)(Relates to Muscle/Fat Ratio)
c. AGE‑ As Age Increases, BMR Decreases
d. AMOUNT OF THYROID HORMONE‑ If TH Increases, BMR Increases (and Vice Versa)
e. BODY TEMPERATURE‑ If Body Temperature Increases (i.e., Fever), BMR Increases (and Vice Versa)
f. DRUGS‑ Stimulants Increase BMR (and Vice Versa)
g. OTHER FACTORS (Miscellaneous)
‑ Emotions, Pregnancy, Lactation All Increase BMR
Discuss Total Metabolic Rate (TMR)
DEFINITION‑ Rate of Catabolism Under Normal Waking Conditions
‑ BMR = 55‑60% of TMR
b. ENERGY USED TO DO SKELETAL MUSCLE WORK
‑ kcals Burned in Exercise/Activity (10‑30% TMR)
c. THERMIC EFFECT OF FOODS
‑ kcals Burned in Metabolizing Foods (10% TMR)
‑ Environmental Temperature (kcals Burned Responding to Temperature Changes)
* NOTE: TMR is Difficult to Determine Because Most of Its Factors Vary From Day to Day
Define energy balance and discuss how it relates to body weight
1.ENERGY BALANCE‑ When Energy Input (kcals in) = Energy Output (kcals burned) in a Given Period
2.RELATIONSHIP TO BODY WEIGHT
* If Energy Input = Energy Output (Energy Balance Maintained)‑‑‑> Body Weight Remains Constant
* If Energy Input > Energy Output ‑‑‑> Body Weight Increases
* If Energy Input < Energy Output ‑‑‑> Body Weight Decreases
* NOTE: Takes 3500 kcals to Synthesize 1 pound of Fat
Describe how weight reduction is best accomplished.
‑ Weight Reduction Best Accomplished By:
1) Decreasing Input
2) Increasing Output (Both Must Be Done in Moderation