HUN2201 STUDY GUIDE EXAM 1

A good source of a nutrient has

10-19% DV per serving

A high or excellent source of a nutrient has

20% DV per serving

Nutrients one should limit should have DV of

5% or lower

Nutrients to limit

Saturated fat, cholesterol, and sodium

High Saturated fat leads to

raised blood cholesterol and heart disease

High Sodium leads to

raised blood pressure and cardiovascular risk

High Cholesterol leads to

heart disease

 Limit added sugars to

<10% of daily calories

Reliable and accurate sources end in

.gov, .edu, .org

List 4 reliable and accurate sources

USDA, NIH, ACS, AHA

Dietary Reference Intakes (DRI): EAR is the

Estimated Average Requirement (below this is deficiency & death)

Dietary Reference Intakes (DRI): RDA is the

Recommended Dietary Allowance

Dietary Reference Intakes (DRI): Between RDA and UL is the

Adequate Intake of a Nutrient

Dietary Reference Intakes (DRI): UL is the

Tolerable Upper Intake Level (above this is toxicity & death)

Draw the DRI graph.

The primary nutrient in dairy is

Calcium (but also Vitamin D)

The primary nutrient in protein is

B12

The primary nutrient in fruits and vegetables is

Vitamin C

Biggest sources of of Food and Nutrition Misinformation

Internet (70%) and media

Explain the development of dental caries.

1) Sugar enters the mouth.

2) Bacteria (Streptococcus mutans) feed on sugars and produce lactic acid.

3) Acids lower ph, demineralizing enamel.

4) If acid attacks continue, enamel breaks down → exposing dentin.

5) Continued demineralization creates a cavity (hole) in the tooth.

Sugar → Streptococcus mutans → acid → enamel erosion → dentin damage → cavity formation.

Gustation

the sensory process that allows us to perceive taste

Gustation works closely with —- to create the perception of flavor.

olfaction (smell)

5 basic tastes

sweet, sour, salty, bitter, umami

How taste works (chemicals, receptors)

·       Chemicals in food bind to receptors on your taste receptor cells in taste buds.

·       Binding triggers a nerve signal to the brain → brain interprets as a specific taste (sweet, salty, etc.).

Sweet taste receptors detect

aldehydes/sugars

Sour taste receptors detect

H+ ions

Salty taste receptors

detect sodium ions (Na+)

Bitter taste receptors detect

alkaloids & nitrogenous compounds —> may signal toxins

Umami taste receptors

detect monosodium glutamate

Nutrient Density Formula

Nutrient density = Nutrient Content/Calories

Streptococcus mutans

Oral bacteria that form plaque and ferment sugars into acid

Helicobacter pylori

Bacteria that colonize the stomach lining; associated with gastritis and peptic ulcers

Lactobacillus acidophilus

Beneficial probiotic bacteria found in the gut and fermented foods; supports digestion and gut microbiome health.

Dysphagia

swallowing process is impaired → bolus of food enters the airway instead of the esophagus.

Results: choking, nasal regurgitation

Higher risk groups: infants, elderly

What does the epiglottis usually do when you swallow

closes to prevent bolus from entering the windpipe (trachea).

Mastication

Chewing food into smaller pieces, mixing with saliva to begin digestion

Deglutition

The process of swallowing, moving a bolus from the mouth → pharynx → esophagus → stomach.

Bolus

a soft mass of chewed food mixed with saliva, ready to swallow

Gastrin

stomach hormone that stimulates parietal cells to release HCl (gastric acid) and chief cells to release pepsinogen.

Pepsinogen

Inactive precursor secreted by chief cells in the stomach; converted by HCl into pepsin, which digests proteins.

Chyme

Semi-liquid mixture of partially digested food + gastric juices in the stomach.

Salivary amylase

Enzyme in saliva that begins chemical digestion of starch into maltose.

Mucous neck cells

secrete mucus + bicarbonate to protect stomach lining from acid.

Parietal cells

secrete HCl (lowers pH, kills microbes, activates pepsinogen) and intrinsic factor (essential for vitamin B12 absorption in the ileum).

Chief cells

secrete pepsinogen (inactive zymogen).

Pepsinogen + HCl →

pepsin

Pepsin

active enzyme that digests proteins into smaller polypeptides

G cells

secrete the hormone gastrin

CCK (Cholecystokinin)

hormone that slows gastric emptying (keeps food in stomach longer).

sends signals to the brain → satiety (feeling full).

Proteins (long chains of amino acids) are broken down by

pepsin into smaller polypeptides.

Gastroparesis

Delayed gastric emptying, often due to nerve damage (e.g., diabetes); causes nausea, vomiting, early satiety.

Aspiration

inhalation of food, liquid, or gastric contents into the airway/lungs

If the stomach’s protective mechanisms fail,

H. pylori infection or NSAIDs can damage mucosa → gastritis or peptic ulcers

What starts protein digestion in the stomach?

HCl denatures proteins and converts pepsinogen → pepsin; pepsin cleaves proteins into smaller polypeptides

Where does most protein digestion finish?

In the small intestine

Dysgeusia

Altered or distorted sense of taste.

Xerostomia

dry mouth; reduced or absent salivary secretion

Peptic Ulcer Disease

ulceration of gastric mucosa.

Mechanism: Breakdown of protective mucosal barriers due to Helicobacter pylori infection, NSAID use, or hyperacidity.

Gastroesophagul Reflux Disease / GERD

Chronic reflux of gastric contents into esophagus.

• LES fails to close properly → gastric acid refluxes into esophagus.

Steps in Protein Digestion

1. Food (bolus) enters the stomach → triggers gastric stretch receptors and presence of protein.

2.     G cells → secrete the hormone gastrin → stimulates parietal cells to release HCl and chief cells to release pepsinogen (inactive zymogen).

3. HCl activates pepsinogen, turning it into pepsin.

4. Pepsin cleaves proteins into smaller polypeptides.

Vitamin B12 Absorption

1.    Parietal cells also secrete intrinsic factor (IF).

2.    Vitamin B12 from food binds to IF in the stomach.

3.    This B12–IF complex travels to the ileum for absorption.

Nutrition-related contributors of GERD:

High fat diet, obesity

Nutrition-related contributors of PUD (ulcer):

Alcohol, NSAIDs, high salt, low antioxidants

Dysgeusia impact on nutrition

decreased appetite and food intake, weight loss, nutrient deficiencies

Xerostomia impact on digestion/absoption

harder to chew and swallow; less starch breakdown

• (Salivary amylase activity decreases → slows starch digestion)

Dental caries impact on nutrition

Painful chewing, avoidance of hard/nutrient-dense foods

Anorexia impact on nutrition

low calorie and nutrient intake

Dysphagia impact on nutrition

Risk of aspiration and choking, Reduced solid/liquid intake

Gastroparesis

Stomach empties food into small intestine more slowly

Gastroparesis impact on nutrition

Early satiety + nausea → reduced food intake, nutrient loss

Type of study that found that high saturated fat and blood cholesterol associated with heart disease.

cohort study

Compare the nutritional value of whole grains to refined (processed) grains.

Whole grains have more fiber.

1 ATP is equivalent to

7 calories

What are the 3 classes of nutrients used to make ATP or energy?

carbohydrates, lipids, and proteins

What are the 6 classes of nutrients?

carbohydrates, lipids, proteins, vitamins, minerals, water

The primary nutrients in grains are

B vitamins, fiber

Observational Studies

no intervention

Case Control Study

group with condition/disease and group without (control group) - go back in time to compare histories.

ex: comparing history of a group of kids with broken bones and group of kids who are healthy to see what caused this difference

Type of study that led to fortification of iodide.

case control

Experimental

have intervention

Randomized Control trial

sample of population, randomly assign to different groups. one receives treatment and one receives placebo. compare outcome

To establish guidelines,

a lot of research studies will be used. best: systematic reviews & meta analysis.

Epithelial cells

type of mucous cell

building blocks of atp: fatty acids, carb, and ??

cariogenic meaning

what step does chyme dump into small intestine during protein digestion

law made for supplements