NUSCTX 10, Midterm 1 - UC Berkeley

Anabolism

Uses energy to construct components of cells.

Catabolism

Breaks down organic matter, for example, to harvest energy.

Nutrient Density

A measure of the nutrient a food provides compared to its energy content.

Trace Minerals

Needed only in tiny amounts.

These minerals participate in most chemical reactions in the body.

These include iron, zinc, iodine, copper, manganese.

Protein Complementation

The act of consuming a variety of plant products to provide all the necessary protein components.

Essential Fatty Acids

Omega-3 and Omega-6 fatty acids.

May reduce the risk of cardiovascular diseases.

Obtained from canola oil, flaxseed oil, cold-water fish, or fish oil.

Metabolism

The set of life-sustaining chemical transformations within the cells of living organisms.

Mitochondrial Matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the citric acid cycle.

Respiration

Is needed to produce a hydrogen (electron-proton) gradient.

Falsifiability

Capable of being tested by experiment or observation.

Endoplasmic Reticulum

A system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids.

Lipid metabolism occurs in Smooth ER

Protein synthesis occurs in Rough ER

Lysosome

A small, round cell structure containing chemicals that break down large food particles into smaller ones.

Enzyme

Biological catalysts that work by lowering the activation energy for a reaction, thus dramatically increasing the rate of the reaction.

Oxidation

A chemical change in which a substance combines with oxygen, as when iron oxidizes, forming rust

Entropy

A quantitative measure of disorder or randomness.

Breaking down.

Villi

Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption.

Calor

Mass(Velocity)

Calorimetry

Direct and indirect are used to measure quantities of heat.

Gross Energy

The total energy intake in the diet.

Metabolizable Energy

Digestible energy minus fecal and urinary energy.

Basal Metabolic Rate

Energy to maintain life processes.

Factors that affect it include: age, growth, height, % lean tissue, fasting, starvation, malnutrition, fever, hormones, and sleep.

70% of total energy use by body depends on lean body mass

Pair-feeding

An experimental method in which food intake or energy (calorie) intake are limited to become same between animal groups and to exclude effects in the animals by differences of food (energy) intake.

Turnover

The movement of something into, through and out of a place, the rate at which a thing is depleted and replaced.

Thyroxine

The main hormone produced by the thyroid gland, acting to increase metabolic rate and so regulating growth and development. Affects BMR.

Adaptive Thermogenesis

Heat production, shivering, excess heat from overeating, adaption to trauma, stress, very different for different people, not usually included in energy calculations.

W^(3/4)

Metabolic rate is proportional to weight (kg) to the 3/4 power

Lumen

A cavity or passage in a tubular organ.

Cephalic

Pertaining to the head.

Autonomic

A subdivision of the peripheral nervous system.

Controls involuntary activity of visceral muscles and internal organs and glands.

Sensory Cells

Specialized cells that react to external stimuli.

Enteric Neuron

The enteric nervous system or intrinsic nervous system is one of the main divisions of the autonomic nervous system and consists of a mesh-like system of neurons that governs the function of the gastrointestinal system.

Active Transport

The movements of ions and molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.

Microvilli

Fingerlike extensions of plasma membrane of apical epithelial cells, increase surface area, aid in absorbtion, exist on every moist epithelia, but most dense in small intestine and kidney

Crypt

A small tubular gland, pit, or recess.

Duodenum

The first part of the small intestine immediately beyond the stomach, leading to the jejunum.

Bicarbonate

A salt containing the anion HCO3

Peristalsis

The involuntary constriction and relaxation of the muscles of the intestine or canal, creating wavelike movements that push the contents of the canal forward.

Bile

Emulsifies fats.

A bitter greenish-brown alkaline fluid that aids digestion and is secreted by the liver and stored in the gallbladder.

Enteropeptidase

The enzyme that catalyzes the activation of trypsin from trypsinogen.

Lymph

A colorless fluid containing white blood cells, that bathes the tissues and drains through the lymphatic system into the bloodstream.

Micelle

An aggregate of molecules in a colloidal solution, such as those formed by detergents.

Splanchnic

Of or relating to the viscera or internal organs, esp. those of the abdomen.

Zymogen

Inactive substance secreted in granules by the pancreas.

It is converted into an enzyme when activated by another enzyme.

Amylase

An enzyme, found chiefly in saliva and pancreatic fluid, that converts starch and glycogen into simple sugars.

Trypsin

A digestive enzyme that breaks down proteins in the small intestine. It is secreted by the pancreas in an inactive form, trypsinogen.

Polypeptide

A linear organic polymer consisting of a large number of amino-acid residues bonded together in a chain, forming part of (of the whole of) a protein molecule.

Acinar

A cell of the pancreatic ductule that occupies the lumen of an acinus; it secretes bicarbonate and water, providing an alkaline pH necessary for enzyme activity in the intestine.

Cholecystokinin

A hormone that is secreted by cells in the duodenum and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas.

Essential Amino Acids

They must be supplied by the diet.

The group of amino acids that cannot be synthesized by the organism but are required by the organism.

Ketogenic Amino Acid

An amino acid that produces ketone bodies following chemical alteration of its carbon skeleton.

Amino Acid Pool

An accumulation of amino acids in the liver and blood that adjusts to meet the body's need for protein and amino acids.

Limiting Amino Acid

The amino acid that is deficient in the diet.

Our bodies use amino acids in a specific ratio to each other, so if a person doesn't get enough of one of them to match with the rest, the rest can only be used at a level to balance with that low one.

Urea

A soluble nitrogenous waste produced in the liver by a metabolic cycle that combines ammonia with carbon dioxide.

The Central Dogma

Information in an organism is encoded in the DNA.

DNA is then copied into RNA.

From the information in the RNA, you can make protein

Denatured Protein

A protein whose structure has been changed by physical or chemical agents.

Protein Efficiency Ratio

Live weight gain/crude protein intake

Kwashiorkor

A condition of protein malnutrition.

Digestibility

A measure of the amount of amino acids absorbed from a given protein intake.

Isocaloric Diet

Test diet and control diets have the same caloric density

True Digestibility

((Neaten-(Nfecal-Nmetabolic))/Neaten)*100

Adequate Intakes

Daily intake amounts set for a nutrient for which there are insufficient research data to establish EAR.

Estimated Average Requirements

Nutrient intake amounts estimated to meet the needs of 50% of the individuals in a group. Used only to evaluate adequacy of diets of groups, not individuals.

Tolerable Upper Intake Levels

Specifies the maximum amount of a nutrient that most people can consume on a daily basis without some adverse effect.

Recommended Dietary Allowances

Daily nutrient intake amount sufficient to meet the needs of 97-98% of individuals in a life stage. Set higher than EARs.

Acceptable Macronutrient Distribution Ranges

A range of intake for each macronutrient, as percent of energy, associated with good health and reduced risk for chronic disease.

Estimated Energy Requirements

The average daily energy needs for life-stage.

Nutrition

The process of obtaining and the assimilation of food necessary for the health, maintenance, growth and reproduction of the organism.

Water

Helps to regulate body temperature, transports nutrients and minerals to cells, rids the body of waste materials, essential to all life processes.

Cellular Respiration

The biochemical pathway by which cells release energy from the chemical bonds of food molecules and provide that energy for the essential processes of life.

Oxidation/Reduction

Losing electrons/gaining electrons

4 Types of Tissue

Muscle

Nervous

Epithelial

Connective

Homeostasis

Internal constancy

Scientific Method

Identify the Problem

Gather Data

Make a Hypothesis

Test the Hypothesis (Experimental)

Does the New Data Agree?

Falsifiable Hypotheses

Testability

Cohort Studies

Involve following groups of people over time. There are two primary purposes for these studies.

Retrospective Studies

Study in which the investigator defines the sample and collects data about the predictor variables after the outcomes have occurred.

Prospective Studies

Study in which the investigator defines the sample and collects data about the predictor variables before any outcomes have occurred.

Calorie

The energy needed to raise the temperature of 1 gram of water through 1 °C

Hess' Law

The total amount of heat produced or consumed when a chemical system changes from an initial state to a final state is independent of the way in which this change is brought about - can't get something from nothing.

Energy Balance

Energy In (the food you eat) - Energy Out (expenditures)

Bomb Calorimetry

Used to estimate energy content of food but does not tell how efficiently our bodies would use a food

Surface Law

The metabolic rate (heat production per unit time) of an animal is proportional to their respective surface area

BMR Prediction by Weight

M=70.5 W^(0.75)

ATP

Adenosine Triphosphate; produced in mitochondria

Gastrointestinal Tract

The gateway where foods becomes a nutrient.

Gastrointestinal Tract Order

Sensory

Esophagus

Liver and Gallbladder

Stomach

Pancreas

Small Intestine

Colon (Large Intestine)

Accessory Organs

Salivary Glands

Liver

Pancreas

Gallbladder

Function of GI Tract

Barrier and immune defense

Fluid and electrolyte absorption

Synthesis and secretion of several proteins (such as apolipoproteins)

Production of bioactive peptides as hormones and neurotransmitters

Hepatic Portal Circulation

The hepatic portal circulation carries blood from the stomach and intestines to the liver.

Nutrients absorbed directly into the blood reach the liver via the hepatic portal vein.

Three Phases of Digestion

Cephalic Phase

Gastric Phase

Intestinal Phase

Stomach Secretions/Enzymes

Cephalic Reflexes

Gastrin

Pepsinogen

Stomatostatin

Pepsin

Intestinal Movement

Propulsion: Peristalsis

Mixing: Segmentation Contractions

Intestine Secretions/Enzymes

Bicarbonate

Goblet cells

Bile

Enteropeptidase

Enterohepatic Circulation

Recycling process in which bile travels from the liver to the gallbladder and then to the small intestine, where it assists digestion.

In the small intestine, most of the bile is reabsorbed and sent back to the liver for reuse.

Proenzymes

Not activated and usually end in -gen

Packages in which the secreted enzymes from the pancreas aggregate

Sources of Protein

In the US, about two-thirds of dietary protein comes from meat, poultry, seafood, eggs, and dairy products

Most of the world relies on plant proteins from grains and vegetables

As a country's economy improves, the proportion of animal foods in the diet tends to increase.

Protein Functions

Fluid balance

Antibodies

Hormones

Enzyme

Structure

Transport

Channels and pumps

Acid-base balance

Types of Amino Acids

Essential Amino Acid

Glucogenic

Ketogenic

Nonessential

Amino Acid Structure

All have a similar structure, but each has a different side chain.

Those that cannot be made in the body, such as leucine, are considered essential.

Protein Structure

Peptide bonds are chemical bonds that link amino acids together

Peptide bonds are formed between the acid group of one amino acid and the nitrogen group of the next amino acid.

Dipeptide bonds are formed between two amino acids.

Polypeptides are formed between many amino acids.

A protein is made of one or more polypeptide chains folded into a three-dimensional shape.