Nutrition Exam 2

[L1] What are the six levels of human-body organization in order?

Chemical → cell → tissue → organ → organ system → organism.

[L1] What is an atom?

Smallest part of an element that retains the element's properties.

[L1] What is a molecule?

Two or more atoms joined by chemical bonds.

[L1] What is a complex molecule?

A large molecule built from smaller molecular subunits, such as glycogen built from glucose.

[L1] What is a condensation reaction?

A make reaction: joins smaller molecules into a larger one while releasing water.

[L1] What is hydrolysis?

A break reaction: uses water to split a larger molecule into smaller ones.

[L1] Which atomic particles are in the nucleus, and what are their charges?

Protons are positive (+); neutrons are neutral (0). Both are in the nucleus.

[L1] Where are electrons and what is their charge?

Electrons carry negative (−) charge and occupy shells outside the nucleus.

[L1] What is the valence shell and octet rule?

Valence shell = outermost electron shell; most atoms are stable when they have eight electrons there.

[L1] What is an element?

A pure substance consisting of one type of atom.

[L1] What makes an atom into an ion?

Gaining or losing electrons causes electrons and protons to be unequal, creating net electrical charge.

[L1] What is a cation and how does it form?

Positively charged ion formed when electrons are lost; example Na+ or K+.

[L1] What is an anion and how does it form?

Negatively charged ion formed when electrons are gained; example Cl−.

[L1] What is an ionic bond?

Electrostatic attraction between oppositely charged ions; example Na+ and Cl− in table salt.

[L1] What is a covalent bond?

Chemical bond formed when atoms share electrons; example the bonds in water.

[L1] How do nonpolar and polar covalent bonds differ?

Nonpolar = equal electron sharing; polar = unequal sharing and partial charges.

[L1] What does hydrophilic mean?

Polar/water-attracting; dissolves or interacts well with water.

[L1] What does hydrophobic mean?

Nonpolar/water-repelling; does not dissolve easily in water, like oil.

[L1] What happens when an acid dissolves in water?

It releases hydrogen cations (H+); acidic solutions have pH below 7.

[L1] What is the pH scale?

Acidic

[L1] Can an alkaline diet simply raise blood pH?

False; buffering systems tightly regulate blood pH.

[L1] What is a buffer and why is it important?

A substance/system that resists changes in pH and maintains homeostasis.

[L1] What are acidosis and alkalosis?

Acidosis = excessively acidic internal conditions; alkalosis = excessively basic conditions.

[L1] What does OIL RIG stand for?

Oxidation Is Loss of electrons; Reduction Is Gain of electrons.

[L1] What is a free radical?

Unstable molecule with an unpaired electron that can react with other molecules.

[L1] How can free radicals cause oxidative stress?

A radical can take an electron from another molecule, oxidizing it and potentially triggering a damaging chain reaction.

[L1] What conditions does the oxidative-stress slide associate with free radicals?

Aging, heart disease, cancer, arthritis and neurodegenerative diseases.

[L1] What is an antioxidant's key role?

Interrupt the free-radical cascade by stabilizing reactive species.

[L1] What does the cell membrane do?

Protective boundary separating intracellular and extracellular environments and regulating movement across the cell.

[L1] What does the smooth endoplasmic reticulum do?

Participates in lipid synthesis; unlike rough ER, lacks attached ribosomes.

[L1] What does rough endoplasmic reticulum do?

Has ribosomes and helps build/process proteins.

[L1] What do lysosomes do?

Digest and recycle proteins, lipids, nucleic acids and cellular waste.

[L1] What is cytoplasm?

Gel-like material inside cells containing organelles and dissolved substances.

[L1] What does the nucleus do?

Contains DNA instructions used in protein synthesis and cell function.

[L1] What do mitochondria do?

Produce most of a cell's usable energy as ATP.

[L1] What are the three passive transport methods?

Simple diffusion, facilitated diffusion and osmosis.

[L1] What is simple diffusion?

Movement of solute directly across a membrane down its concentration gradient, without ATP.

[L1] What is facilitated diffusion?

Substance moves down its gradient through a membrane transport protein, without ATP.

[L1] What is osmosis?

Water moves through a selectively permeable membrane toward higher solute concentration.

[L1] What are the four primary tissue types?

Epithelial, connective, muscle and neural/nervous tissue.

[L1] What does epithelial tissue do?

Covers and lines body surfaces, organs and cavities; protection, secretion and absorption.

[L1] What does connective tissue do?

Supports, binds and protects structures; includes bone, blood and adipose tissue.

[L1] Which tissue contracts and shortens for movement?

Muscle tissue.

[L1] What does nervous/neural tissue do?

Receives and transmits signals for communication and control.

[L1] What defines an organ?

A group of different tissues coordinated to perform functions, such as the stomach.

[L1] Which organ filters blood to remove wastes and balance some nutrients?

Kidneys.

[L1] What is an organ system?

Multiple organs working together; the digestive system includes GI tract organs plus accessory organs.

[L2] What is the GI tract?

Continuous tube from mouth through esophagus, stomach, small intestine, large intestine, rectum and anus.

[L2] Give the passage of food through the digestive tract.

Mouth → esophagus → stomach → duodenum → jejunum → ileum → cecum/colon → rectum → anus.

[L2] What are the four layers of the GI tract wall?

Mucosa, submucosa, muscularis and serosa, from inner to outer.

[L2] What are circular and longitudinal GI muscles for?

Mixing and propelling digestive contents through contractions.

[L2] What are four accessory digestive organs?

Salivary glands, liver, gallbladder and pancreas.

[L2] Which organ produces bile and which stores it?

Liver produces bile; gallbladder stores and concentrates bile.

[L2] What does the pancreas secrete to support digestion?

Digestive enzymes (such as amylase, lipase and proteases) and bicarbonate that neutralizes acid.

[L2] What do salivary glands release?

Saliva to moisten food and initiate enzymatic starch digestion.

[L2] What do GI sphincters do?

Rings of muscle regulate forward movement and prevent inappropriate backflow of food.

[L2] What causes gastroesophageal reflux (GERD)?

Weakening/improper closing of the gastroesophageal sphincter permits acidic stomach contents to flow into the esophagus.

[L2] What is a bolus?

Chewed food mixed with saliva that can be swallowed.

[L2] What is chyme?

Semi-liquid mixture of partially digested food and stomach secretions.

[L2] What are the three small-intestine sections?

Duodenum, jejunum and ileum.

[L2] What are major colon regions identified in the digestive-path slide?

Cecum, ascending, transverse, descending and sigmoid colon.

[L2] About how long does the lecture estimate food transit from mouth to anus?

Approximately 24-72 hours, with individual variation.

[L2] What is mechanical digestion?

Physical breakdown and movement of food without splitting chemical bonds.

[L2] What is chemical digestion?

Enzymes and other substances split chemical bonds to produce smaller nutrient molecules.

[L2] What is mastication?

Chewing, an example of mechanical digestion.

[L2] What is peristalsis?

Wave-like contractions that propel food forward.

[L2] What is segmentation?

Alternating intestinal contractions that mix the contents with digestive secretions.

[L2] What is the general function of a digestive enzyme?

Speeds a specific chemical reaction that breaks food compounds into absorbable components; many end in -ase.

[L2] Why is stomach hydrochloric acid (HCl) useful?

Kills many microbes, helps activate protein-digesting enzymes and denatures dietary proteins.

[L2] What causes lactose intolerance?

Insufficient lactase to break lactose into simpler sugars.

[L2] What is the cephalic phase of digestion?

Early sensory/brain signals prepare the GI tract for incoming food—its 'wake-up call.'

[L2] What digestion happens in the mouth?

Mastication mechanically breaks food; salivary amylase begins starch chemical digestion.

[L2] Why is the stomach important for mechanical digestion?

Peristaltic contractions churn food and mix it with gastric juices.

[L2] Why is HCl important in stomach digestion?

It kills pathogens, activates digestive enzymes and helps digest/denature dietary proteins: all listed choices.

[L2] Where does most chemical digestion and nutrient absorption happen?

Small intestine.

[L2] What is bicarbonate's role in the duodenum?

Pancreatic bicarbonate helps neutralize acidic chyme from the stomach.

[L2] What does bile do during fat digestion?

Emulsifies fat droplets so lipase can digest them more efficiently; bile is not an enzyme.

[L2] Why do villi and microvilli aid absorption?

They greatly expand surface area at the intestinal brush border.

[L2] What are enterocytes?

Absorptive cells lining the small intestine.

[L2] What is celiac disease?

Autoimmune inflammatory reaction to gluten in wheat, rye and barley that damages villi and reduces absorption.

[L2] Which nutrients generally enter blood circulation after absorption?

Carbohydrate digestion products, amino acids, minerals and water-soluble vitamins.

[L2] Which absorbed nutrients are commonly transported in the lymphatic system?

Most dietary fats and certain fat-soluble vitamins.

[L2] What are main functions of the large intestine?

Absorption of water/electrolytes, storage of waste and excretion of feces.

[L2] What is the gut microbiome and where is it concentrated?

Community of microbes, most abundant in the large intestine; they help ferment undigested substrates.

[L2] How does inflammatory bowel disease (IBD) differ from irritable bowel syndrome (IBS)?

IBD causes chronic inflammation and potential intestinal injury; IBS causes functional symptoms without characteristic inflammatory damage.

[L2] What are examples of IBD?

Crohn's disease and ulcerative colitis.

[L2] What symptoms can IBS cause according to the lecture?

Abdominal pain, bloating, diarrhea and discomfort without inflammatory bowel injury.

[L2] Which organ/location is most important for nutrient absorption?

Small intestine, particularly its villi/microvilli-containing surface.

[L2] Which digestive structures have food physically pass through them vs not?

Food travels through GI tract; accessory organs produce/store helpful secretions without food entering them.

[L3] How many kcal per gram do carbohydrates provide?

4 kcal/g.

[L3] What elements compose carbohydrates?

Carbon, hydrogen and oxygen.

[L3] List major food sources of carbohydrates.

Grains/starches, fruits, vegetables, dairy, legumes/beans, sweets and desserts.

[L3] What are major functions of carbohydrates in food and the body?

Energy, fiber, sweetness/flavor, supporting intestinal health, sparing protein for other uses.

[L3] What distinguishes simple from complex carbohydrates?

Simple = 1-2 sugar units (mono/disaccharides); complex = longer chains (oligo/polysaccharides).

[L3] What is an oligosaccharide?

A carbohydrate made of roughly 3-10 sugar units (lecture classification).

[L3] Name the three monosaccharides.

Glucose, fructose and galactose.

[L3] What is glucose and where is it found?

Most abundant circulating monosaccharide/blood sugar; present in fruits, vegetables and honey.

[L3] What is fructose?

Simple sugar found in fruit, vegetables and honey.

[L3] What is galactose?

Monosaccharide that is a component of milk sugar (lactose).

[L3] What chemical formula appears for monosaccharides on the slide?

C6H12O6.