Nutrition and Food Choices Overview

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Questions and Answers

Which of the following is a group of essential amino acids?

Methionine, valine, and sodium

Leucine, isoleucine, and threonine (correct)

Iron, zinc, and potassium

Lysine, tryptophan, and calcium

What distinguishes macro-minerals from micro (trace) minerals?

Macro-minerals are organic while micro-minerals are inorganic.

Macro-minerals include vitamins, while micro-minerals include amino acids.

Macro-minerals can be synthesized by the body, whereas micro-minerals cannot.

Macro-minerals are needed in relatively large amounts, while micro-minerals are needed in smaller amounts. (correct)

Which statement correctly describes vitamins?

Vitamins can be produced in sufficient quantities by the human body.

Vitamins are always synthetic compounds.

Vitamins serve as the primary source of energy for bodily functions.

Vitamins are non-caloric and essential for chemical reactions in the body. (correct)

Which of the following statements is true regarding water as a nutrient?

Water is the simplest nutrient but also the most important. (A) Signup and view all the answers

Which of the following vitamins can the human body synthesize?

Vitamin D (C) Signup and view all the answers

Which of the following pairs are classified as micro (trace) minerals?

Iron and zinc (A) Signup and view all the answers

What percentage of total body water in a 73 kg man is typically found in the intracellular compartment?

60% (A) Signup and view all the answers

What is the primary composition of starch in cereal grains, potatoes, and legumes?

80 to 85% amylopectin and 15 to 20% amylose (A) Signup and view all the answers

What type of glycosidic bonds does amylopectin contain?

Both (1-4) and (1-6) glycosidic bonds (B) Signup and view all the answers

What is the role of glycogen in the human body during prolonged fasting?

To regulate glycemia by releasing glucose into circulation (D) Signup and view all the answers

Why is carbohydrate loading advantageous for athletes before long distance races?

It boosts glycogen levels in muscles for sustained energy (D) Signup and view all the answers

Why is cellulose not digestible by humans?

It is linked by B (1-4) glycosidic bonds (D) Signup and view all the answers

What condition may occur if gallstones block the pancreatic duct?

Pancreatitis (B) Signup and view all the answers

Which of the following substances stimulates pancreatic exocrine secretions?

Secretin (B) Signup and view all the answers

What is the primary function of the large intestine?

Absorb water and electrolytes (D) Signup and view all the answers

How much fluid can the large intestine absorb per day?

5 to 7 liters (D) Signup and view all the answers

Which of the following is NOT one of the pancreatic enzymes?

Lactase (B) Signup and view all the answers

What is the tube that makes up most of the large intestine called?

Colon (A) Signup and view all the answers

Which factor is NOT a stimulus for the secretion of HCl in the stomach?

Fatty acids (B) Signup and view all the answers

What type of cells in the pancreas release pancreatic juice?

Exocrine cells (C) Signup and view all the answers

What role does cellulose play in the large intestine?

Help maintain bowel movements (A) Signup and view all the answers

What accounts for the majority of gastric acid secretion during digestion?

Gastric phase (A) Signup and view all the answers

Which digestive enzyme is primarily responsible for fat digestion?

Lipase (A) Signup and view all the answers

What is the role of gastrin in the stomach?

Directly stimulates oxyntic cells for acid secretion (D) Signup and view all the answers

What is the function of the crypts of Lieberkuhn in the large intestine?

Secrete mucus (A) Signup and view all the answers

During fasting, gastric acid is secreted at what percentage of its maximal rate?

10 - 15% (C) Signup and view all the answers

At what pH range is pepsin activated?

Between 1.5 and 2.5 (A) Signup and view all the answers

What mechanism protects the stomach from its own acidic environment?

Production of thick alkaline mucus (A) Signup and view all the answers

What triggers the cephalic phase of gastric secretion?

Thoughts and smells of food (C) Signup and view all the answers

Which enzyme is inactivated in the highly acidic environment of the stomach?

Alpha-amylase (A) Signup and view all the answers

Which two bile acids comprise the primary bile acids in the body?

Chenodeoxycholic and cholic acids (D) Signup and view all the answers

What are bile acids conjugated with to improve the formation of micelles?

Glycine and taurine (B) Signup and view all the answers

What role do bile acids and salts play during fat digestion?

They emulsify fat globules into smaller droplets. (D) Signup and view all the answers

What is one of the main functions of bile besides digesting lipids?

To excrete organic hydrophobic substances (C) Signup and view all the answers

How does the gallbladder concentrate bile?

Through the absorption of water, sodium, and electrolytes (A) Signup and view all the answers

Which hormone triggers the release of bile from the gallbladder into the small intestine?

Cholecystokinin (CCK) (A) Signup and view all the answers

What is formed when bile becomes supersaturated with cholesterol?

Gallstones (B) Signup and view all the answers

What component does the liver conjugate bilirubin with for bile secretion?

Glucuronic acid (A) Signup and view all the answers

In what form do bile salts exist after the conjugation of bile acids?

Salts of sodium and potassium (D) Signup and view all the answers

Which statement about the gallbladder is accurate?

It concentrates bile by absorbing various substances. (C) Signup and view all the answers

Study Notes

Nutrition

Nutrition is the study of how the body uses nutrients for energy, growth and regulation at the cell, tissue, and whole-body levels.
It encompasses food composition, ingestion, digestion, absorption and transport of nutrients and functions, and disposal of byproducts of metabolism.
The science of nutrition is evolving with more evidence-based research to replace older questionnaires and correlational studies that lack data precision and reliable variables.

Food Choices

Individual responses to food vary, so a "one-size fits all" approach seldom works; identifying diets tailored to individual needs is essential.
Animal activism, climate issues, and religious beliefs often influence dietary choices and can lead to confusion and diversion from preventive health promotion.
Randomized Clinical Trials are valuable; they allow for more control and give superior quality data when studying the effects of specific foods/nutrients on health or disease.

Composition of the Human Body

The human body is formed of approximately 27 elements.
The most common elements are Oxygen, Carbon, Hydrogen and Nitrogen which comprise 63%,18%, 9% and 3% respectively.
Water constitutes 55-65% of body mass, and protein and lipids together contribute about 30-40%
Nucleic acids, carbohydrates, and other organic molecules make up the remaining 1%, and minerals account for 5%.

Introduction to Macronutrients

Carbohydrates: Made of carbon, hydrogen, and oxygen, primarily used as fuel (starch and sugars).
Lipids: Fats and oils are essential for various bodily functions (energy storage, insulation, cell signaling, etc), also carrying fat-soluble vitamins (A, D, E, K); the primary lipids are triacylglycerols, and phospholipids.
Proteins: Organic compounds composed of amino acids; used in various cellular processes (structure, function). Of particular importance are amino acids such as leucine, tryptophan, methionine, valine and phenylalanine, isoleucine, threonine.

Introduction to Micronutrients

Minerals: Essential inorganic substances in health (macrominerals like calcium, sodium, chloride, potassium, etc.), and micro(trace) minerals, like iron, zinc etc
Vitamins: Organic substances that facilitate important chemical reactions in the body; vitamins are classified into fatsoluble and water-soluble vitamins.

Digestion and Absorption

Digestion begins in the mouth (chewing and saliva); the stomach further mixes food.
The small intestine is where most digestion and absorption happens, using enzymes and digestive juices; this is supported by accessory organs such as the pancreas.
The large intestine absorbs water and electrolytes, and stores indigestible material prior to excretion.

Importance of Water

Water is essential, and we can survive longer without other nutrients than water.
It facilitates various bodily functions and a key component of the body's transport system.
It is divided into compartments like intracellular, extracellular (interstital and plasma) and transcellular fluids.

Brain Metabolism

The brain has a high metabolic rate, relying primarily on glucose for energy.
The blood-brain barrier restricts fat usage, therefore the brain strongly relies on glucose for its energy needs.
Insulin does not affect the amount of glucose absorbed in the brain but plays a role in other parts of the body.

Homeostasis of Glucose

Normal glucose levels are maintained through the interplay of insulin, glucagon, and other hormones,
Insulin promotes glucose uptake by cells, while glucagon increases glucose levels
Glucose homeostasis is influenced by both hormonal and neural controls.

The Glycemic Index (GI)

Glycemic index (GI) measures how quickly a food causes an increase in blood sugar levels.
Glycemic Load (GL) is similar but accounts for portion size.
Foods with high GI can trigger large rises blood sugar and influence related comorbidities.

Fiber in the Diet

Fiber is any carbohydrate that cannot be digested or absorbed by the human body.
It has many beneficial effects on digestion and health overall including cholesterol reduction and gut health.
Types of fiber include soluble and insoluble types which serve different functions.

Importance of the Gut Microbiota

The gut microbiota contains a diverse and vast collection of microorganisms.
This community plays essential metabolic roles (production of certain vitamins).
Gut-microbiota is influenced by the food choice, and these changes may cause significant issues.

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Description

This quiz explores the fundamental concepts of nutrition, focusing on how nutrients are utilized by the body. It examines the importance of individualized dietary choices and the impact of various factors such as animal activism and climate on these decisions. Additionally, it highlights the role of randomized clinical trials in nutritional research.