Bio Exam 4

Importance of water balance in large intestine

-too much water removed -> waste becomes too solid -> constipation -not enough water removed -> waste becomes too liquid -> diarrhea

What does food break down into when passing through the small intestine?

1. Amino acids (proteins) 2. Fatty acids (fats) 3. Simple sugars (carbs -> sugars) -broken down into the components; small enough to be absorbed into the bloodstream

How type II diabetes works

1. Blood sugar is too high 2. Pancreas secretes more insulin 3. Cells become less sensitive to insulin 4. Pancreas secretes even more insulin 5. Pancreas's insulin secreting cells become worn out & don't secrete insulin as well 6. Type II diabetes

6 types of nutrients

1. Carbohydrates 2. Fats 3. Proteins 4. Vitamins 5. Minerals 6. Water

Ingestion

1. Food is initially broken down in the mouth 2. Food is moved to the stomach through the esophagus

Digestion

1. Food travels down the esophagus to the stomach 2. Stomach breaks down food both physically & chemically 3. Then continued to small intestine where the pancreas aids digestion - formed into chyme 4. The liver & gallbladder helps break down the fats (Technically Digestion begins with the saliva in the mouth during ingestion, but food gets further broken down in the stomach)

2 chemicals produced by the gastric glands

1. Hydrochloric acid 2. Pepsinogen

Process of converting food into nutrients

1. Ingestion 2. Digestion 3. Reabsorption 4. Elimination

Most people aren't required to supplement vitamins & minerals other than in what circumstances?

1. Menstruation (iron) 2. Post-menopause (calcium) 3. Low calorie or restricted diets 4. Pregnancy (folate)

2 functions of pancreas

1. Neutralizes stomach acid 2. Further breaks down carbohydrates & proteins (and to a lesser extend, fats)

Ruminant digestion

1. Ruminants grind tough plant material with their large, flat teeth 2. The ruminant swallows the food & it enters the first chambers of the stomach, the rumen 3. Chewing the cud-the ruminant regurgitates some of the food & chews it again, further breaking down plant cell walls so beneficial cellulose digesting bacteria can access & digest all the cellulose (regurgitated food=cud) 4. The cud is swallowed again & further broken down in the rumen, before continuing on through the digesting system

Important functions of water in the body

1. Transporting nutrients & waste 2. Taking part in chemical reactions 3. Serves as a solvent for many vitamins, minerals, amino acids, & sugars 4. Lubrication of joints & other tissues/organs 5. Temperature regulation

kilocalorie (kcal)

1000 calories

Fat lbs -> kcal

1lb of fat = 3600 kcal (Burn 3600 kcal to lose 1 lb of fat)

Glycogen

A complex sugar made up of many glucose molecules; the form in which carbohydrates are stored in liver and muscle tissue -water is bound to glycogen & is lost when it uses energy

diabetes

A condition in which an individual does not adequately regulate their blood sugar levels -not producing enough insulin and/or not responding to the insulin being produced

Chyme

A creamy, acidic mixture of digested food that passes from the stomach into the small intestine

epiglottis

A flap of cartilage that functions like a trap door, closing as you swallow to prevent food from entering the trachea

Complete protein

A food containing all 9 essential amino acids (for humans) -same amount of protein but different combinations of amino acids

ruminant

A mammal with a four chambered stomach that chew a cud of regurgitated, partially digested food; not all herbivorous mammals are ruminant, most have cloven feet

Pepsinogen

A molecule that is quickly converted into pepsin

Cellulose

A plant carbohydrate found in plant cells walls that contains large amounts of potential energy in its chemical bonds; most animals don't have enzymes to digest cellulose, so its eliminated with other fiber

Enzyme

A protein that acts as a catalyst -specific shape -> specific molecules (fits like a puzzle piece) -spreads up the specific chemical reactions

sphincter

A ring of muscle that opens & closes passages in the body (at end of digestion as well as throughout the digestive system)

Pyloric sphincter

A ring of muscle that opens & closes to allow chyme to move from the stomach to the small intestine

Small intestines

A thin tube about 20 ft long in which chyme is slowly digested further into nutrients

Large intestine

A tube-like organ much shorter but wider than the small intestine, in which water, salts, & some vitamins are absorbed, & wastes come together to be eliminated (colon)

Which group would a tick belong to? A. Carnivorous B. Herbivorous C. Omnivores

A. Carnivorous (eat the blood)

Which type of gland are the gastric glands? A. Exocrine B. Endocrine

A. Exocrine (not a hormone)

Which of these is NOT one of the 6 types of nutrients? A. Fiber B. Water C. Vitamins D. Fats

A. Fiber

If salt concentrations regulate water movement into & out of the colon, & constipation is caused by loss of water, what must laxatives do to salt concentrations in the colon? A. Laxatives increase salt concentrations in the colon B. Laxatives decrease salt concentrations in the colon

A. Laxatives increase salt concentrations in the colon -as salt concentrations increase, water will travel back towards the large intestine instead of to other body parts causing less constipation

Bile is secreted by the __ and helps to digest food in the __ A. Liver, small intestine B. Pancreas, small intestine C. Pancreas, stomach D. Gallbladder, small intestine

A. Liver, small intestine

Digestion starts in the ____ A. Mouth B. Esophagus C. Stomach D. Small intestine

A. Mouth

The movement of digested food between the stomach and small intestines is controlled by the ___. A. Pyloric sphincter B. Gastric pits C. Sub-esophageal sphincter D. Epiglottis

A. Pyloric sphincter

Carbohydrates are ___ A. Sugars B. Fats C. Proteins D. Minerals

A. Sugars

What is the definition of a calorie? A. The energy needed to raise the temperature of 1 gram of water by 1 degree Celsius B. The amount of energy stored in ATP in food C. The amount of ATP in food D. The energy required to produce one ATP molecule

A. The energy needed to raise the temperature of 1 gram of water by 1 degree Celsius

Essential amino acids

Amino acids that are not produced by the body & need to come from food (9 essential)

non-essential amino acids

Amino acids that can be produced by the body (11 non-essential)

Food deserts

An area with limited access to affordable & nutritious food -major health concern -low income & very rural areas -less likely to have grocery stores forcing people to get their food from convenience stores -relying on highly processed & high calorie foods leading to obesity & other health problems related to nutrition

Pepsin

An enzyme that breaks proteins down into amino acids (building blocks of the proteins/components) -Chemical breakdown of food

Liver

An organ located near the connection between the stomach & small intestine that secretes bile into the gallbladder

Pancreas

An organ located near where the stomach & small intestines meet that secretes pancreatic juice into the small intestines (helps control pH)

omnivorous

Animals that consume both plants and animals

carnivorous

Animals that consume only other animals (ex: mosquito/ticks enter human skin & drink the blood)

Herbivores

Animals that consume only plants (can be just certain plant parts)

What is a complete protein? A. A complex protein molecule that has not yet been digested into its amino acid building blocks B. A food containing all 9 essential amino acids C. A food containing all 20 essential amino acids D. A single amino acid

B. A food containing all 9 essential amino acids

If you go on a diet, you may appear to lose a lot of weight at first (according to the scale), but that weight loss is actually mostly water. This happens because water molecules are bound to stored ___, and when it is broken down those water molecules are lost. A. Fat B. Sugar C. Lipids D. Proteins

B. Sugar

Bile

Breaks apart globs of fat so they can be digested by the pancreatic juices

What are the building blocks of proteins? A. Enzymes B. Fatty acids C. Amino acids D. Simple sugars

C. Amino acids

What type of tissue lines the stomach? A. Connective tissue B. Muscle tissue C. Epithelial tissue D. Nervous tissue

C. Epithelial tissue - protective barrier like the skin

Many bottles in the Erotylidae family mostly eat fungi. Which group would they belong to? A. Carnivorous B. Herbivores C. Omnivores

C. Omnivores

What is the organisms basal metabolic rate? A. The energy expended during physical exercise B. The energy an organism needs to grow to adulthood C. The energy the organism spends at rest in the thermoneutral zone D. The total energy an organism uses in a day

C. The energy the organism spends at rest in the thermoneutral zone

Disaccharides

Carbohydrates composed of two simple sugars, that take longer to break down & release energy

Risks of obesity

Cardiovascular disease, respiratory disease, stroke, diabetes, & certain cancers

Gastric pits

Cervices covering the lining of the stomach

Lower esophageal sphincter

Closes after food enters to stomach to prevent stomach acid from traveling up the esophagus (Prevents black flow- would cause heart burn if backflow occurs)

BMR varies between what different factors?

Composition, genetics, gender, health conditions, activity level, age (affects how many calories needed to intake per individual)

Digestion in the stomach

Contractions of the muscles around the stomach physically churn & break down food; stomach acid breaks down food chemically & kills bacteria

fat

Dense & contain twice as much energy as carbohydrates (stored long term) -hydrophobic: stored without water & water isn't lost when broke down

Type II diabetes

Develops when blood sugar levels are chronically too high (90% of cases causes obesity)

Trans fats

Different arrangement of their hydrogen molecules & can increase low density lipoproteins, leading to plaque buildup in blood vessels, & eventually cardiovascular diseases

saturated fats

Each carbon molecule is bonded to two hydrogen molecules (saturated with hydrogen); stable & less likely to react, so more likely to be stored as fat -2 hydrogen bonded -too much= excess weight gain

Gastric glands

Epithelial glands that are at the bottom of the gastric pits & secrete stomach acid

essential fatty acids

Fats that are not produced by the body & need to come from food

Non-essential fatty acids

Fats that can be produced by the body

What is poop made of?

Fiber, water, bile, & dead microorganisms

Villi

Finger like projections in the small intestine that increase surface area for absorption (larger projections)

Type I diabetes

Generally genetic, & the pancreas does not secrete enough insulin to reduce blood sugar levels

Obesity in the US

Greatest health concerns in the US with nearly 40% adults are considered obese & that percentage has risen over time

Hydrochloric acid

Has a very low pH and corrodes proteins in the food into smaller pieces (Breaks down into smaller proteins)

cecum

Houses cellulose digesting bacteria; start of the large intestine & is found in all mammals but is reduced in carnivores & many omnivores -in many herbivorous & some omnivorous animals including horses, rodents, rabbits, & koalas

Hydrophobic

Hydro= water Phobic= avoidant

If there's a higher concentration of salt in the colon which way will the water move, into the colon or out of the colon?

Into the colon

Koala vs human cecum

Koala- 2 meter long projection of the large intestine Human- small out cropping

Complex sugars

Large, complex carbohydrate molecules that are broken down even more slowly (stored the longest causing you to stay full longer)

Proteins

Long chains of amino acids that are used as building blocks in the body, and can also serve as enzymes (produces chemical reactions)

Bacteria in large intestines

Majority of bacteria in the body is found in the large intestine/colon & live off of what body can't digest which helps absorb the waste with secretion of chemicals & vitamins & won't hurt our body (important for human health)

Iron is an element, so it is composed of a single iron atom rather than a molecule composed of multiple elements. Knowing this, is iron a vitamin or a mineral?

Mineral

Is the epiglottis a sphincter?

No -Epiglottis -> flap of cartilage -Sphincter -> ring of muscle

Insulin

Protein that regulates a negative feedback loop; produced in the pancreas

Feedback loops regulating "fullness"

Regulation of hunger & fullness is largely determined by genetics; some genetic mutations can cause individuals to not feel full or not feel full as quickly as others

If you are trying not to gain weight, which type of fat should you avoid and why?

Saturated fats, because they are more stable molecules and less likely to chemically react, making them more likely to be stored as body fat

Vitamins & minerals

Serve as reaction catalysts & can be rescues, so they don't need to be consumed in large amounts -doesn't provide useable energy

simple sugars

Small carbohydrates that are easily and quickly broken down to release energy (don't store energy as long)

unsaturated fats

Some carbon molecules are bonded to only one hydrogen; less stable & more likely to participate in chemical reactions, making them less likely to be stored as fat

Carbohydrates

Sugars composed of carbon, oxygen, and hydrogen that are broken down to produce energy for the body; short term energy storage (Most energy used for fuel)

Cellulose digesting enzymes

Termites produce celluloses (enzymes that break down cellulose) & also have many beneficial bacteria in their gut that help breakdown the cellulose in wood

Basic metabolic rate (BMR)

The energy an organism expends at rest, in temperatures within the thermoneutral zone, without digesting food (at rest w/ no physical activity)

Calorie

The energy required to raise the temperature of 1g of water by 1 degrees Celsius (Can show how much to heat up water & burn food)

Rumen

The first chamber of a ruminants stomach, which contains cellulose digesting enzymes & cellulose digesting bacteria

Why does surface area make absorption more efficient?

The greater the surface area in the small intestine lining has the more efficient the absorption can happen -Flat surface: only 12 molecules can pass through into the cell at a time -Increase surface area: 18 molecules can pass through in a section of the same length

Absorption

The process by which energy rich molecules & other nutrients are taken up from the digestive tract into the bloodstream, so they can be delivered to cells around the body -some molecules including alcohol & aspirin can be absorbed into the blood stream directly from the stomach but most absorption occurs in the small intestine

Digestion

The process by which food is broken down into macro molecular components

Body Mass Index (BMI)

The ratio of a person's height & weight, often used to determine if a person is at a healthy weight (doesn't take into account muscle mass or fat distribution)

Nutrients

The useable macromolecules from food

Microvilli

Tiny projections on cells in the small intestine that further increase surface area for absorption (small projections)

Difference between vitamins & minerals

Vitamins= organic compounds (multiple atoms connected to carbon creating the carbon backbone) Minerals= elements (single atom)

How does salt concentrations in the colon regulate water absorption?

Water is absorbed from the colon, so the concentration of salts in the colon compared to the blood controls movement of water in & out

Peristalsis

Waves of smooth muscle contractions

Why digestion has a major impact on overall body function?

level of sugar in blood & energy delivered in cells directly impacts mood & brain function/ ability to perform or pay attention can be reduced when not eating