Chapter 10 Flashcards
Chemicals from food you eat are used to….
provide building blocks to build molecules, to generate energy for your body’s activities, & to assemble essential nutrients that your body cannot produce.
Food supplies over ___ substances that your body needs but cannot produce itself
40
Nutrients are
the chemicals in the food you eat that help your body perform all its functions
- there are 6 types of nutrients in food: carbohydrates, proteins, fats, vitamins, minerals, & water.
Macronutrients are
nutrients that you need in large amounts daily.
- Macronutrients = Carbohydrates, proteins, fats, & water
Micronutrients are
nutrients that you need less of on a daily basis
-Micronutrients = Most vitamins & minerals
The food you eat usually contains _______ & ______ molecules
large, complex
- they are too big to pass through cell membranes & are not exactly the same as the smaller ones found in your body
- the digestive system must dissemble the food you eat into smaller molecules –> these molecules then become sources of energy, or assemble them into more complex molecules & use them to build and maintain cell structure and function.
- Ex. cheese is made up of proteins that are too large for our cells to use in their present state. Your digestive system dissembles them into their basic “building block” molecules. Your cells then use them to build your own proteins
All organisms use the ______ components to make their molecules
same
- Ex. lions, pandas, humans, & trees make their proteins from the same 20 kinds of building block molecules
Carbohydrates are (3)
compounds made up of Carbon, Hydrogen, & Oxygen atoms and are major source of energy for your body.
- U can use carbs as an energy source just minutes after a meal or u can store them for later use
- Foods with simple carbs include sugars from fruit, honey, milk
Glucose is (4)
is a type of sugar molecule that is a major source of fuel supply for the work done by your cells
- ur cells break down glucose molecules & extract their stored energy
- ur cells use carbon chains of simple sugars as raw material to manufacture other kinds of molecules
- glucose molecules that ur cells don’t use immediately are incorporated into larger carbs or are used to make fat molecules
Starches are
complex carbs.
- they are found in foods like whole-grain cereals, bread, rice, & potatoes.
- complex carbs are broken down by ur digestive system into simple sugars –> the simple sugars are absorbed into blood & carried to cells in the body –> excess blood sugar is converted into glycogen
Glycogen is (3)
a chain of many glucose molecules
- in humans, most glycogen is stored in the liver and in muscle & fat cells. –> When the body needs energy, it breaks down glycogen, releasing glucose.
Fibre/Cellulose (3)
is a type of complex carb
- our digestive system can’t break it down but u need it to include it in ur diet as fibre supplied bulk to help ur muscles move food & wastes through ur digestive system.
- they may have other benefits like reducing the risk of heart disease.
A protein is (5)
a complex molecule that is constructed from 20 kinds of smaller molecules called amino acids
- they contribute to almost all ur day-to-day functions. Ex. proteins form hair & muscles, and they provide long-term nutrient storage
- some proteins circulate in the blood & defend the body from harmful micro-organisms
- Other proteins convey messages from one cell to another
- some proteins work with enzymes to control the chemical reactions in a cell
Enzymes are
proteins that speed up specific chemical reactions without being consumed in the reaction
Essential amino acids (5)
are the 8 amino acids that your cells cannot make from other molecules
- if u lack even 1 essential amino acid, you cannot make protein properly.
- Animal products like meat, milk, eggs, & cheese provide all 8 essential amino acids
- those that don’t eat animal products must eat combinations of plant foods to obtain all the essential amino acids
- some vegetarian combos of complete protein include corn & beans, rice & lentils, and hummus with pita bread
Fats (5)
AKA lipids
- are molecules formed from fatty acids & glycerol.
- fats store energy in ur body & help ur body absorb fat-soluble vitamins.
- fatty tissues cushion ur organs & provide ur body with insulation.
- there are several types of fat
Saturated Fats (5)
have only single bonds between carbon atoms in the fatty acids
- Each of these carbon atoms has the maximum number of hydrogen atoms, so the fat is called “saturated”
- Saturated fats= most animal fats like lard & butter
- Diets rich in saturated fats may promote fat deposit build-ups in blood vessel walls which can reduce blood flow & contribute to heart disease.
- Only a small percentage of ur daily intake of fats should be saturated fats
Unsaturated Fats
have at least one double bond in a fatty acid chain so we say it’s “unsaturated”
- found in fruits, vegetables, nuts, seeds, & fish
- Unsaturated fats like olive oil & sunflower seed oil, are usually liquids @ room temp
- Small amounts of unsaturated fats are an important part of a healthy diet
Trans Fats
AKA Hydrogenated fats
- they are unsaturated fats have been hydrogenated, meaning they have been processed to accept more hydrogen atoms
- they are solid @ room temp & have a longer shelf life than other unsaturated fats. –> Ex. margarine that is solid @ room temp is trans fat
- They are often used in frying fast foods
- they should be avoided as consuming trans fats as they contribute to heart disease & other health problems
Vitamins are
organic nutrients that u need in small amounts to regulate ur body processes & perform chemical reactions
- organic nutrients = nutrients that contain carbon
- if u picture carbs, proteins, & fats as building blocks, vitamins are the tools to help put them together.
What are the 2 types of vitamins?
water-soluble & fat-soluble
- water-soluble vitamins cannot be stored in ur body & should be included in ur everyday diet. Ex. vitamin C, the B vitamins
- small amounts of fat-solube vitamins can be stored in the fatty tissue of ur body for future use. Ex. Vitamins A, D, E, K
Minerals are
inorganic nutrients & do not contain carbon
- u need a variety of minerals in ur diet like calcium, iron, phosphorus, copper, sodium, & zinc to perform many different tasks. –> Ex. u use calcium to make bones & teeth.
- u need to consume mineral-rich foods each day to replace the minerals u lose in sweat, urine, & digestive waste
Vitamins & , minerals are found naturally in
many foods like meat, eggs, dairy products, whole-grain products, tofu, green leafy vegetables, & some fruit
- people who are not able to eat enough of a variety of foods from the basic groups sometimes take vitamin & mineral supplements
- however large doses of vitamin & mineral supplements may be harmful, so its important to read the recommended dose on labels & consult ur heath practitioner.se
Why is water the most important nutrient?
- ur every cell needs water to complete its processes
- many of the body’s chemical reactions take place in water
- water makes up the bulk of blood,
extra-cellular fluid, & other bodily fluids - many guides recommend 1litre of water daily–> more when ur physically active or its hot
- without enough water to replace what u lose through sweat, urine, & respiration, u can suffer from dehydration, which leads to problems with many body systems
Converting food into energy
- During cellular respiration, molecules like glucose make cellular energy by reacting with oxygen.
- 40% of energy from food is converted into energy for performing cell functions
- 60% is converted into thermal energy, radiating from ur body as heat –> heat generated by cellular respiration is not wasted: retaining some heat enables ur body to regulate its temp.
–> when exercising, ur cells increase cellular respiration rate. That’s why u feel warm after exercising. —> ur body loses heat through sweating & other cooling methods.
When u sit in class, u radiate about as much heat as a ______ light bulb
100-W
A calorie is
the amount of energy required to raise the temp of 1g of water by 1 degrees Celsius.
Dietary Calories
calories u will learn about in this unit
- written with an uppercase C
- 1 dietary calorie = 1000 calories
Calories in fats, carbs, & protein
Fats are energy rich: 9 calories per gram
Carbs & proteins: 4 calories per gram
WHY?
- The carbon atoms in fats usually have more carbon-to-hydrogen bonds than carbon atoms in carbs or proteins. –> breaking these bonds releases a great deal of energy, so a 1g of fat releases more energy than 1g of protein or carbs
Female teenagers need ______ calories & male teenagers need ______ calories for the basic metabolic processes that sustain life plus energy for an active lifestyle.
2200, 2500
Daily physical activity of at least ____ minutes helps burn any excess calories & maintain a healthful weight. It also strengthens the _______, _______, & _________.
30, heart, bones, muscles
Nutrient Vs percentage of total daily calories recommended
Carbs: 45-65%
proteins: 10-30%
Fats: 25-35%
The science of nutrition is the study of …..
food & its effects on the body
Nutrition Labels
- Health Canada requires that nutritional info be placed in a standardized manner on all packaged foods in order to identify the nutritional value –> they show nutrient contents & nutritional claims in a format that is easy to read & understand
- reading them helps track daily requirements for important nutrients like dietary fibre, protein, vitamins, & healthy fats as well as unhealthy fats, sugar, & sodium that contribute to heart disease, high bp, & stroke
A nutraceutical is
- is a substance that is purified from foods and taken like a medicine to provide health benefits including disease prevention. Ex. omega-3 fish oil pill that’s taken as a supplement
- called nutraceuticals or functional foods is a new food industry that’s based on the idea that foods can be disease-fighters
Functional Food is
a food that has health benefits, including disease prevention, that are beyond the normal nutritional benefit of the food
- Fruit & veggies with high levels of vitamin A, C, E, & beta-carotene are identified as good candidates
- Orange juice: rich in calcium, Eggs: rich in omega-3, milk: rich in vitamin D
- Ex. Study by National Cancer Institute in the USA states that foods like garlic, cabbage, carrots, licorice, soy, & ginger as possible cancer-fighters.
- Ex. wheat bran can reduce risk of colon & breast cancer.
- rn Canada has 100s of companies in food industry & is becoming a world leader in such foods supply
Probiotics are
foods that contain substances that support health and that may help to strengthen the body’s natural defence against disease
- Probiotic products like probiotic yogurt, help increase beneficial bacteria back into the large intestine
- it is one of the fastest-growing areas of dietary products
The search to understand how our bodies digest food actually began ___________ of years ago
hundreds
- In 1700s, Lazzaro Spallanzani (natural history proff) devised a simple experiment to determine how food is broken down. –> subjects (humans & birds) swallowed a small sponge attached to a thread. after time, he pulled out the sponge to examine. –> He observed that the juice that filled the sponge could break down meat. –> concluded that an area in the body produced special juice that could digest food
- Spallanzani’s theory debunked the previously held theory that food was “cooked” in the heat of stomach and that’s how it is broken down.
- Scientists today, who use technology now, are “standing on the shoulders” of curious thinkers like Spallanzani who lived 100s of years ago
Industry experts expect that there will be continued growth in the “_________” food business
Designer
- the demand for food designed to fight disease will increase as consumers become more knowledgeable about health benefits of foods & rising health care cost
Canada’s Food Guide to Healthy Eating
- It provides the public with needed info to make healthy food choices
- Recommended servings on PAGE 283
- According to the guide …
1 serving of vegetables & fruit= medium fruit or 125mL vegetables
1 serving of grain = 1/2 bagel, or small waffle
1 serving of milk & alternatives = 200mL milk, or 200mL yogurt
1 serving meat & alternatives = 30mL peanut butter or 75g chicken - Other guidelines in TABLE ON PAGE 283
To eat in a healthy way, you need to eat the _____ foods & the ____________ of different foods
right, right amount
What are the 4 stages of Food Processing? (just list them in order of occurrence)
1) Ingestion
2) Digestion
3) Absorption
4) Elimination
Stages of Food Processing: Ingestion
- it’s the act of eating or drinking
Stages of Food Processing: Digestion
- it’s the process of breaking food down into molecules that are small enough for the body to absorb
- There are 2 types of digestion: Mechanical & Chemical
Mechanical Digestion
like chewing & churning of stomach, grinds food into smaller pieces, increasing it’s surface area (which makes chemical digestion easier)
Chemical Digestion
- is breaking the chemical bonds within the large molecules of carbs, fats, & proteins into smaller molecules during hydrolysis
Hydrolysis is
a process that breaks bonds in food molecules by adding water to them in the presence of specific enzymes.
What is each Macronutrient broken down into?
Fat –> glycerol + fatty acids = used to build fats
Protein –> amino acids = used to build proteins
Carbs –> sugars (like glucose) = source of energy & source of chain of carbon atoms that ur body can used to construct other molecules containing carbon.
Stages of Food Processing: Absorption
- It’s when cells absorb small molecules like amino acids and simple sugars in the small intestine.
- from there, they enter the circulatory system where the molecules are transported in the blood to body cells, where they combine to make bigger molecules or are broken down to provide energy.
- If there are more molecules then needed immediately, they are converted into fat for storage.
Stages of Food Processing: Elimination
- It’s the process of removing from the digestive tract any undigested materials. –> these materials travel through the large intestine & are eliminated as feces.
In a digestive sac,…
food enters and wastes exit through the same opening
- Ex. a sea anemone has a digestive sac
An Alimentary Canal is
AKA gastrointestinal tract
a digestive tract with 2 openings, a mouth & an anus
–> Food enters through the mouth at one end and is churned & mixed as it travels along the tube. –> Further along, nutrients are absorbed from the digested food & then the wastes are disposed through the anus
- Alimentary canals are more efficient than digestive sacs for obtaining nutrients from food as it has more specialized regions for processing food.
- more complex animals have an alimentary canal
Alimentary Canal Length
- The length of an animal’s alimentary canal is often correlated with diet.
–> typically herbivores & omnivores have longer alimentary canals, relative to their body size, than omnivores –> this is cuz vegetation is harder to digest as it has cell walls. –> longer alimentary canal provides more time for digestion & more surface area of nutrient absorption. - In humans & many others, the alimentary canal is much longer than distance between mouth & anus. –> Ex. A person 1.8m tall can have a 9-m alimentary tract. It fits cuz portions with & loop back & forth
If the body is made out of the nutrients u digest, how do we prevent self-digestion?
- by digesting food in specialized organs
6 main organs that make up the alimentary canal
- mouth, pharynx, esophagus, stomach, small intestine, & large intestine
Accessory organs & glands of digestive system
include salivary glands, pancreas, liver, & gallbladder, which secrete digestive juices in the alimentary canal
6 Main Organs: Mouth
- functions in ingestion & beginning of digestion
- teeth & tongue = mechanical digestion
–> tongue moves food towards teeth and down the throat
–> Incisors, cuspids, & bicuspids cut into & tear food.
–> molars grind & crush food into fine paste, making it easier to swallow & increases surface area for easier chemical digestion - the salivary glands secrete saliva for chemical digestion
6 Main Organs: Pharynx is
the upper portion of the throat. It’s a short tube shared by the digestive & respiratory system
- when u swallow, the epiglottis (a cartilage flap) temporarily seals off the airway & prevents the food from moving into the air passageway as it passes through the pharynx & into the esophagus.
In a typical day, salivary glands in your mouth secrete more than ___ of saliva
1L
Saliva is
a watery liquid that contains digestive enzymes, mucus, & other chemicals to chemically digest food in mouth
- Digestive enzymes in saliva include amylase, which breaks down chemical bonds in starches (a carb), like pasta & bread, to form sugars. –> that’s y if u chew on starchy food for long, it will taste sweet.
- Another enzyme, lysozyme, helps fight infection by digesting cell walls of bacteria that may enter the mouth.
- mucus (a sticky substance) in saliva, lubricates food so that it can slide down the tube without harming the tissues that line the tube.
- Chemicals in saliva neutralize certain acids in food, preventing teeth from decay
- saliva also moistens food & makes it easier to chew.
Bolus is
chewed clump of food
6 Main Organs: Esophagus is
a long, muscle-encased tube which connects the pharynx to the stomach
- Even though the esophagus is vertically oriented in the body, gravity plays no role in pushing the bolus down the esophagus –> instead, its pushed through peristalsis
Peristalsis
is the involuntary contraction and relaxation of longitudinal and circular muscles in a wave-like motion throughout the digestive tract, allowing for the propulsion of the food from the pharynx to the anus
a sphinctor is
a muscular valve that acts like a door.
- GOOGLE: A ring-shaped muscle that relaxes or tightens to open or close a passage or opening in the body
Heartburn
- not related to heart
- a sphincter at the end of the esophagus (cardiac sphinctor) closes to keep food from coming back up the stomach.
- if this muscle opens at inappropriate times, like when u overeating, acid from the stomach can flow back into the esophagus, causing a burning sensation: heartburn
6 Main Organs: Stomach is
an elastic, muscular sac that continues the chemical & mechanical digestion of food.
- with accordion-like folds & highly elastic wall, ur stomach can stretch to hold up to 2L of food & drink, enough for ur body’s needs for many hours
Chemical Digestion in Stomach
- bolus is bathed in gastric juice
- HCI in gastric juice breaks apart the cells in food & kills bacteria swallowed with food
- 1 gastric enzyme, pepsin, helps break large protein molecules into smaller molecules
- Mucus lubricates & protects the stomach wall from the HCI, preventing stomach from eating itself.–> even with mucus, cells of stomach are eroded and every 3 days, enough new cells are generated to completely replace the stomach lining.
- gastric glands don’t secrete gastric juice constantly. –> when u see, smell, or taste food, a brain signal is sent to ur stomach to stimulate the gastric glands to secrete gastric juice.
–> ur gastric glands secrete up to 3L of gastric juice daily.
Mechanical Digestion in Stomach
- about every 20 seconds, the stomach contents are mixed by churning of stomach wall. –> turns bolus into acid-rich liquid called chyme.
- The muscles contract, creating churning motion that stirs the chyme & eventually forces it into small intestine –> flow of chyme into small intestine is regulated by a sphincter.
- it typically takes 2-6 hours for the stomach to empty.
6 Main Organs: Small Intestine is
a long (6m), narrow (2.5 cm) tube where digestion is completed & absorption of most nutrients takes place.
- Digestion takes place in first portion, and absorption takes place along the rest of the length.
- peristalsis move chyme along the intestine, a journey that takes about 3-5 hours
Digestion in Small Intestine
first part of small intestine = duodenum
- fats are undigested till the duodenum cuz they are insoluble in water
So how do fats undergo hydrolysis?
- in duodenum, chyme mixes with several digestive juices like bile.
–> Although bile has no enzymes, it has substances that prepares fats for hydrolysis –> fats tend to clump together, making it difficult for enzymes to reach the molecules (less surface area). –> bile separates small fat droplets, which enables digestive enzymes to break down fats more efficiently
- Pancreatic juice contains enzymes that further break down carbs, proteins, & fats.
- Pancreatic enzymes, along with enzymes secreted by the lining of the small intestine, complete the chemical digestion of food.
Bile is
a yellow or greenish alkaline liquid produced by liver (body’s greatest internal organ)
- bile is stored in a sac-like structure called the gallbladder until it’s secreted into the duodenum
Pancreatic juice is
a clear alkaline liquid that neutralizes the acidic chyme & contains enzymes that further break down carbs, proteins, & fats.
- Pancreatic enzymes, along with enzymes secreted by the lining of the small intestine, complete the chemical digestion of food.
Absorption in Small Intestine
- the small intestine is highly specialized for absorbing nutrients –> its wall is folded into many small finger-like projections called villi (singular villus). The cells lining each villus have microscopic projections called microvilli.
- the villi increase the surface area of intestine, making absorption more efficient
- at its core, each villus has a network of microscopic blood vessels & a small lymph vessel.
–> once fatty acids & glycerol are absorbed, these building blocks are recombined into fats that are then transported into the lymph vessel.
–> Sugar & amino acids are absorbed into bloodstream through blood vessels in each villus
Where does the nutrient-rich blood travel to once absorbed into bloodstream by the blood vessels in villi? (2)
-nutrient-rich blood from small intestine travels to liver, where many nutrients are converted into new substances like protein.
- The liver also modifies & detoxifies substances absorbed by the digestive tract before the blood carries these materials to the heart for distribution to the rest of the body.
6 Main Organs: Large Intestine is (6)
AKA colon
is a short (1.5m) wide (5cm) tube
- undigested food passes through a sphincter from the small intestine to this one.
- As material enters the large intestine, it passes by a small sac-like organ called appendix –> in some mammals, the appendix processes cellulose & other materials. –> In humans, the appendix contains white blood cells & plays a role in immunity.
- the large intestine absorbs any access water from this waste, making it more solid
- the wastes move along colon by peristalsis, taking about 12-24 hours
Water absorption in large intestine (3)
- Saliva, gastric juice, & other digestive juices contain large amounts of water. –> together, about 7L of fluid are secreted into the alimentary canal each day –> some is absorbed with nutrients in small intestine
- the large intestine absorbs most of the remaining water
- together, the small & large intestine absorbs 90% of the water that enters the alimentary canal
Feces are
undigested food material and other waste products
the rectum is
the final portion of the large intestine/ colon
How is digestive waste removed from the body (2)
- feces are stored in rectum until they can be eliminated.
- 2 rectal sphincters, 1 voluntary & other involuntary, regulate the opening of the anus
Bacteria in colon produce …. (2)
important vitamins, including vitamin K & some B vitamins
- these vitamins are absorbed into the bloodstream from the colon.
Discomfort in digestive system can be caused by ….
eating too much, eating too quickly, or eating an inappropriate combination of foods
Gas in the digestive system is a result of… (2)
swallowed air or the breakdown of undigested food in colon
- Gas is made of odourless CO2, oxygen, hydrogen, & nitrogen –> when it’s passed through the rectum, it also includes small amounts of sulphur produced by bacteria there & the gas may smell unpleasant
Persistent or intensive discomfort in digestive system may be caused by….
inflammation, infection, malabsorption (difficulty in the digestion or absorption of nutrients from food), or another disorder
Endoscopy (3)
is when a narrow tube is inserted into the throat & passed into the esophagus, stomach, & upper intestine
- a small camera in the narrow tube enables the doctor to see the internal structures & to identify abnormalities
- sometimes the tube has tiny scissors that are used to cut a small piece of tissue for viewing under a microscope (biopsy)
A biopsy is (2)
Google: a procedure to remove a piece of tissue or a sample of cells from your body so that it can be tested in a laboratory.
- A biopsy is used to determine if the cells are normal & can also identify presence of Helicobacter pylori bacteria, which burrow into the stomach wall & cause inflammation.
Colonoscopy is (3)
when a thin, lighted tube with an attached camera is inserted through the rectum
- used to diagnose intestinal disorders, as it allows doctors to see further along the intestines
- if unusual growth is detected, the doctor may opt for a biopsy. –> if the biopsy indicates that the cells are abnormal or cancerous, it’s sometimes possible to surgically remove those cells during the diagnostic procedure
A less invasive diagnostic tool to examine digestive tract is… (2)
a procedure where the patient swallows a pill that contains a camera. Called “pill cam” or capsule endoscope
–> the pill proceeds through the intestines, it takes pics of the structures. –> the pill is later eliminated in feces/
Sum table on 295
The leading cause of death in Canadian adult men & women is _____________________
Cardiovascular Disease
Cardiovascular Disease is (2)
any disease that affects the heart & blood vessels.
- research shows that certain cardiovascular diseases cause changes to the lining of arteries, reducing the blood flow rate. –> when flow of blood in arteries is restricted, the cells cannot always obtain necessary nutrients efficiently & cell function is reduced or ceases.
“Laughter is the best medicine” (4)
- stressful experiences can decrease the diameter of arteries, causing cardiovascular diseases
- Scientists have investigated changes in the rate of blood flow in arteries before & after exposure to laughing. Also investigated the effects to joyful music.
–> in both types of experiments, results showed an increase in arterial diameter - Essentially, including positive & joyful experiences in our daily lives could be good medicine
All the cells in an animal need to ___________________, _______________, & ______________________ (3)
gain nutrients, exchange gases, remove waste products
- some aquatic animals that have bodies only a few cells thick, transport materials across their cell membrane to & from their environment
- larger animals use an internal transport system to bring resources close enough to all cells for exchange of materials to occur
- Most animals have a CIRCULATORY SYSTEM that transports oxygen & carbon dioxide, distributes nutrients to cells, & removes cellular wastes.
Your cells need a constant supply of ___________ & ___________
nutrients, oxygen
The 3 primary components of the circulatory system are the __________, ___________, & _________________
blood, heart, blood vessels
- blood is pumped by the heart into the blood vessels
