BIO-135 Exam 1

Describe the design of a case-control study (a type of observational study often seen in the health fields)

A case-control study is a type of observational study where two groups of people, one with the outcome under study, and one without the outcome are compared.

What is the definition of a nutrient? How do the definitions of "non-essential nutrient" and "essential nutrient" differ? In other words, what is true about both non-essential nutrients and essential nutrients and what is true about an essential nutrient that is not true of other (non- essential) nutrients?

A nutrient is a substance found in foods that is required for maintenance of health and proper body function. Essential nutrients are components that our body cannot make, thus, we get it from the food we digest. Non-essential nutrients are substances our body makes itself.

How does a standard food differ from a functional food? Do you think such a distinction should be made? Keep this question in mind as you proceed through the course.

A standard food is one that provides basic nutrition. A functional food is one that has added health benefits beyond just basic nutrition.

What is the agency that regulates food labels for most processed foods?

Food and Drug Administration (FDA).

What is the difference between a food and a nutrient? Is bread a food or a nutrient?

Food is defined as one which may provide health benefits beyond basic nutrition. A nutrient is a component found in foods that are required for the maintenance of health and proper body function. Bread is considered food in this scenario.

What do we mean when we say that something (i.e. smoking) is a risk factor for hypertension, certain cancers and cardiovascular disease? What is the difference between a "cause" and a "risk factor"?

In the medical field, a "risk factor" is a behavior, a genetic predisposition or some other element that can increase a person's chances of developing a disease. For example, smoking cigarettes is a risk factor for developing lung cancer. Not every person who smokes cigarettes will develop lung cancer, but people who do smoke have higher chances of developing lung cancer then non-smokers. Further, obesity is a risk factor for heart disease but not all individuals who are obese will develop heart disease. In contrast, a "cause" is some factor that will specifically lead to a particular disease. For example, severe lack of vitamin B3 over time will cause Pellagra. Those that lack vitamin B3 for an extended period of time will develop Pellagra because it is caused by vitamin B3 deficiency. In summary, risk factors do not result in diseases or conditions in every case, but "causes" do

In an intervention study, what is the difference between the experimental or test group and the control group?

In this type of study the experimental group and control group are compared to one another and the main difference between these two is that, in an experimental group there different variables are changing, and with the control group it stays the same that's why it's called controlled.

What are the basic functions of nutrients?

Nutrients have many functions. The macronutrients (Digestible carbohydrates, triglycerides (fat) and protein) can be broken down to provide chemical energy in the form of ATP. In other words, they provide the body with kcalories. Micronutrients have regulatory functions that vary with the individual nutrient. For example, vitamin D helps regulate blood calcium levels and Iodine is a mineral that is part of key thyroid hormones. Some minerals also provide structure for the body. For example, calcium provides structure for bones.

Identify the steps in the scientific process. Give an example of each step.

Observation: This is a question based on what is being seen. An example would be seeing a flashlight that is not turning on. First, the person would observe the broken flashlight and wonder why the flashlight is not working. From that, they would come up with a series of multiple hypotheses to later test. Hypothesis: This is an explanation for whatever was observed. An example is maybe the flashlight is missing batteries or maybe the bulb is broken. Experiment: This tests the hypothesis, so the person would put new batteries in or check if the lights bulb is working seeing which of the two is the solution to the problem.

What subunits (smaller chemical groups) make up fat (triglyceride)? Carbohydrates? Proteins?

Triglyceride is made up of fatty acids. Examples: margarine, saturated fats, red meats carbohydrates are made up of sugars. Examples: whole grains, whole fruits proteins are made up of amino acids. Amino acids are basic components of living cells.

The means of absorption that requires energy is called

active transport

Food entering the small intestinal tract needs to be neutralized by this organ/process

bicarbonate from the pancreas

Identify some ways to determine if a nutrition-related website is likely to be reliable.

credibility of the source should be one of the most important factors in determining the legitimacy of a source, as well as consistency of informatio

The food is prevented from going into the windpipe by the

epiglottis

Heartburn (acid reflux) can happen if the ___________________ sphincter does not close properly

gastroesophageal

What does the EER tell us? Who sets this recommendation? How accurate is this number?

he EER is the Estimated Energy Requirement. The EER gives an estimate of the number of calories an individual needs to keep a stable, healthy weight. The National Academies sets the recommendation. The number is more of a recommendation because there are so many factors hat go into the number. For example, age, gender, weight, height, and level of physical activity all help to determine EER.

The cell membrane bilayer is made largely of

lipids

The organ that compounds usually reach first after they are absorbed into the bloodstream is the

liver

Bile is produced in the ___________ and stored in the ________________.

liver, gallbladder

The sum of all the reactions in the body is referred to as

metabolism

The organelle where the macronutrients are broken down to produce energy is called the

mitochondria

Both the kidney and the liver help deal with substances that are toxic or in excess in the blood but the kidney differs from the liver in that the kidney

sends waste products out of the body

The microvilli cell can be found at the surface of the

small intestines

Bicarbonate is secreted into the _______ by the ____________ to neutralize the acidic contents coming from the stomach

small intestines, pancreas

Cells of similar types can group together to form: A. tissues B. molecules C. compounds D. systems E. organs

tissues

This organelle is where proteins are actually constructed by linking together amino acids

ribosome

What are the acceptable macronutrient distribution ranges (AMDR) for carbohydrates, protein and fat? Who sets these recommendations? Why are the carbohydrate and fat guidelines given as a percent of kcalories rather than a gram amount? (note that there is both an AMDR and an RDA for protein)

AMDR is defined as the acceptable macronutrient distribution range. These ranges exist for nutrients such as carborhydrates, fats and proteins. The DRI makes the recommendations of what the range distributions for the macronutrients should be. The percentage range for carbohydrates is 45-65%. The AMDR range for proteins is 10-35% and for fats it is 20-35%. Macronutrient ranges are given in a percentage of calories because the proportion of nutrient intake in diets are more important than the overall amountd. Percentages help with the diet's overall balance

What is the unit of measure for each class of nutrients? Which nutrients are considered macronutrients? micronutrients?

All of the macronutrients are measured in grams or kilograms because they're needed in larger quantities than micronutrients. Macronutrients include carbohydrates, proteins, lipids, and water. Micronutrients are measured in milligrams or micrograms since they're needed in small amounts. Micronutrients are vitamins and minerals.

What is the difference between an intervention study and an observational study in terms of design?

An Observation Study has Case-Control studies that identify patterns of patients with certain conditions to patients without it. There is no intervening with diets, behavior, etc. In an Intervention Study patients are tested through clinical trials. In the clinical trials patients are grouped into Experimental and Control Groups. The Experimental Groups are intervened with in their dietary intake, behavior, etc. In the Control Groups there is nothing changed and they are monitored.

What principles do you need to follow to be sure that your intervention study has the strongest design possible?

An intervention study should include an experimental group and a control group. The experimental group is the group that is manipulated, and the results are then recorded. The control group is used to compare and helps to determine a conclusion for the results.

Describe the basic diet planning principles of balance, moderation, variety and nutrient density.

Balance, in the world of dieting, is the practice of balancing between the food groups when choosing your meals throughout the day. Balance in your diet could also mean balancing the amount of calorie intake and calorie use in your body(like the use of calories to workout and do other physical activity). Moderation in the world of dieting means to simply not over-eat or under-eat. It also conveys to not eat too much of one thing (like binging on pizza). Variety is the incorporation of all the various food groups and nutrients accompanied with them. Nutrient density is the amount of nutrients contained in a certain food. For example, a ripe apple picked straight from the tree has more nutrients than processed applesauce.

What are the basic atoms or elements in carbohydrate, protein, fat (triglyceride), vitamins?

Carbohydrates - Hydrogen, Carbon, Oxygen Protein - Nitrogen, Carbon, Hydrogen, Oxygen Fats - Glycerol, Hydrogen, Carbon Vitamins - Carbon, Hydrogen, Oxygen

This compound forms our genes and chromosomes and tells the body

DNA

Give an example of a positive correlation and a negative correlation.

Example of positive correlation: As alcohol consumption increases, blood alcohol level increases. Example of negative correlation: As speeding increases, good gas mileage decreases.

How do intervention studies differ from non-intervention studies in terms of what you can conclude from the findings?

Interventional studies requires the experimental team to change or manage the experimental portion of the experiment. Theses studies focus on the outcome of the manipulated variable and usually has a control group or exstensive prior research to compare it's findings to. A non-interventional study could be considered purely observational. Non-interventional stidues usually require long term data over time and there is nothing changed by the reseachers. The findings in an interventional study yields a more concrete comparison of what differed between the experimental and control groups, while non-interventional studies show change over time.

What are the two major food-related guidance documents issued by the government?

My Plate and Dietary Guidelines for Americans.

Identify the 6 classes of nutrients. How many kcalories are associated with each class of nutrients? Which nutrients are organic?

Nutrients are classified in 6 different ways and then divided into two separate groups. There are four macronutrients and two micronutrients. Carbohydrates and proteins are measured as 4 kcal/gram, and lipids are measured as 9 kcal/gram.

How does a nutrient differ from a phytochemical or zoochemical?

Nutrients are components found in the foods we consume. Phytochemicals are chemicals that directly come from the plants we consume.

What type of studies are commonly used to determine the EAR requirement for a nutrient in a given population?

One type of study used to determine Estimated Average Requirements is a Depletion and Repletion study. In this type of study, the nutrient in question is removed from the participant's diets until symptoms of deficiencies occur. Then, the nutrient is slowly added back to their diets until the symptoms of deficiency are no longer prevalent. Another study used is a Balance study, where the intake amount of a nutrient is compared to how much of it is secreted. The average intake amount before the nutrient begins being secreted tells researchers that most people need an amount within 1 standard deviation of that average.

What is meant by optimal nutrition? undernutrition? overnutrition? malnutrition?

Optimal nutrition is obtaining the right amount of nutrients. Our genetic makeup is going to determine what that optimal amount will entail. Undernutrition is the state of being deficient in one or more nutrients Overnutrition is consuming too much of one or more nutrients or kcalories Malnutrition is either the state of undernutrition or overnutrition, when the nutrient intake or energy intake is either too little or too high.

Describe the Dietary Reference Intakes. Who sets these recommendations? What are the specific guidelines under the DRI umbrella (i.e. EAR, RDA, etc.)? Describe the meaning or interpretation of each of these guidelines.

The Dietary Reference Intakes (DRIs) are recommendations for the amount of energy, nutrients, and other food components that healthy people should consume in order to stay healthy, reduce the risk of chronic disease, and prevent deficiencies. The World Health Organization and the Food and Agriculture Organizations of the United Nations, and other organizations concerned with international health published a set of dietary standards to apply worldwide. Estimated Average Requirements used to evaluate nutrient intake of populations. Recommended Dietary Allowance and Adequate Intakes used for individual goals for individual intakes and to plan individual diets. Tolerable Upper Intake Levels recommended limit for nutrient toxicities.

How do the Harvard and Mediterranean food guides differ from the USDA food guide? Be able to compare and contrast these three Food Guides (Post thoughts to the discussion forum and get feedback from others)

The Harvard guide puts more emphasis on whole grains, and the dairy group is not emphasized. The mediterranean diet pyramid puts a huge emphasis on fruits and vegetables, included in the same category is nuts, legumes and seeds. I also noticed that in the mediterranean food guide they included drinking water and enjoying meals with others while other the other two food guides did not. They all made sure to put that red meats and sweets should be consumed sparingly.

What is the difference between a research question, a hypothesis, and a scientific theory?

The difference between these three things are that, a hypothesis is basically an educated guess which can be testable and also able to be falsifiable. A research question is pretty much someone just thinking about something particular in the world and in their mind thinking of an idea. Finally, a scientific theory is something that's tested and it's based facts that's been examination of facts, which can be confirmed through different observations.

What are the two leading causes of death in the United States? Which of the leading causes of death in the US is at least partially related to diet?

The two leading causes of death in the United States are heart disease and cancer (lecture 1, page 8). I would argue that both heart disease and cancer are partially related to diet.

All the substances within the lumen of the GI tract are

not in the body

The process where water flows through a semi-permeable membrane from an area where there are less dissolved substances to an area of more dissolved substances is called

osmosis

When chyme moves out of the stomach, it passes through the

pyloric sphincter