WEEK 3 - TOPIC 1-3: Protein; Food Insecurity & Hunger; Sustainable Food Systems

Vocabulary flashcards covering key terms from Week 3 notes: protein basics, digestion, nitrogen balance, plant-based protein concepts, food insecurity, and sustainable food systems.

Protein

Macromolecule containing carbon, hydrogen, oxygen, and nitrogen; essential for growth and repair; large chains of amino acids; nitrogen-containing.

Amino Acid

Building blocks of protein; consist of an amino group (NH2), a carboxyl group (COOH), and a distinctive side chain (R).

Amino Group

NH2 group on an amino acid; one of the key functional groups.

Carboxyl Group

COOH group on an amino acid; one of the key functional groups.

Side Chain (R Group)

The unique group attached to each amino acid that determines its properties and function.

Primary Structure

The unique sequence of amino acids in a protein.

Secondary Structure

Local folding patterns of the polypeptide chain (e.g., alpha helices and beta sheets).

Tertiary Structure

The overall three-dimensional shape of a single polypeptide.

Quaternary Structure

The arrangement of multiple polypeptide subunits in a protein.

Essential Amino Acids

Nine AAs that cannot be synthesized in adequate amounts by the body: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Nonessential Amino Acids

Amino acids that the body can synthesize and are not required in the diet under normal conditions.

Conditionally Essential Amino Acids

AAs normally nonessential but required from the diet in special circumstances (e.g., illness or stress).

Protein Synthesis

The cellular process of building proteins based on genetic instructions (involves transcription and translation).

Mutual Supplementation

Combining two or more plant protein sources to provide all essential amino acids.

Complementary Proteins

Two or more incomplete protein sources that together supply all essential amino acids.

Complete Protein

Protein source that contains all essential amino acids in adequate amounts.

Incomplete Protein

Protein source that lacks one or more essential amino acids.

High-Quality Protein

Dietary protein with all essential amino acids in the right proportions and high digestibility.

Limiting Amino Acid

The essential amino acid present in the lowest amount in a protein source, limiting protein synthesis.

Polypeptide

A chain of amino acids bonded together; part of or the whole protein.

Dipeptide

Two amino acids linked by a single peptide bond.

Tripeptide

Three amino acids linked by peptide bonds.

Hydrochloric Acid (HCl)

Strong stomach acid that helps break down proteins and activate enzymes.

Pepsin

Stomach enzyme that begins protein digestion in the presence of HCl.

Edema

Swelling caused by fluid leakage; can occur with protein deficiency.

Nitrogen Balance

Assessment of protein metabolism by comparing nitrogen intake with nitrogen losses (urine, feces, sweat).

Positive Nitrogen Balance

Nitrogen intake exceeds losses; occurs in growth, pregnancy, and bodybuilding.

Negative Nitrogen Balance

Nitrogen losses exceed intake; occurs with illness, malnutrition, trauma.

Equilibrium (Nitrogen Balance)

Nitrogen intake equals nitrogen losses; typical in healthy adults.

Food Security

Access to a sufficient quantity of affordable, nutritious food for an active, healthy life.

Food Insecurity

Limited or uncertain availability of nutritionally adequate and safe foods.

Hunger

Recurrent and involuntary lack of access to food; physical sensation of needing food.

Availability

Sufficient quantities of food available on a consistent basis.

Access

Economic and physical ability to obtain appropriate foods.

Utilization

Proper biological use of food: energy and nutrients, clean water, sanitation.

Stability

Access to food at all times, despite economic or climatic changes.

SNAP (Supplemental Nutrition Assistance Program)

Federal program providing funds to low-income individuals/families to purchase food; eligibility ≤130% of poverty.

WIC (Women, Infants, Children)

Nutrition education and food packages for pregnant/nursing women and children up to age 5; income ≤185% of poverty.

National School Lunch Program

Free or reduced-price meals for school children; eligibility up to 130% (free) or 185% (reduced) of poverty.

School Breakfast Program

Free or reduced-price breakfasts for school children; similar eligibility to Lunch.

Emergency Food System

Networks of anti-hunger organizations, food banks, soup kitchens, and shelters providing food to those in need.

Thrifty Food Plan

USDA plan for a low-cost nutritious diet; basis for SNAP benefit levels and poverty line; updated periodically.

Poverty Line

Minimum income considered adequate; used to determine eligibility for programs; based on the Thrifty Food Plan.

Minnesota Semi-Starvation Study

WWII-era study where volunteers were studied to understand starvation effects and rehabilitation needs.

Planetary Health Diet

Diet emphasizing plant-based foods with limited animal products to reduce environmental impact.

Greenhouse Gases

CO2, CH4, and N2O released by agricultural systems and related activities.

Soil Health

Quality of soil that supports nutrient-dense crops, water retention, and climate resilience.

USDA Organic Certification

Certification for organic farming: no synthetic pesticides/fertilizers; no GMOs; emphasizes soil health and animal welfare.

Fair Trade

Movement/market model promoting fair prices and social/environmental standards for producers.

Community Supported Agriculture (CSA)

Consumers buy shares of a farm’s harvest in advance and receive regular produce.

Farmers’ Markets

Direct-to-consumer markets where farmers sell produce; often higher farmer share of revenue.

Permaculture

Sustainable design approach inspired by natural ecosystems to create resilient food systems.

Regenerative Agriculture

Farming practices that restore soil health, biodiversity, and ecosystem services.