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MP2 POWERPOINT Living Environment. Period 4 12/07/12 1. Attendance 2. Test today 1. No electronics during or after the test. 2. Sit facing front. 3. No.

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Presentation on theme: "MP2 POWERPOINT Living Environment. Period 4 12/07/12 1. Attendance 2. Test today 1. No electronics during or after the test. 2. Sit facing front. 3. No."— Presentation transcript:

1 MP2 POWERPOINT Living Environment

2 Period 4 12/07/12 1. Attendance 2. Test today 1. No electronics during or after the test. 2. Sit facing front. 3. No talking or disturbing others. 4. Raise your hand if you have a question 1. Although – please don’t ask me to explain how to do a question! 2

3 Homeostasis a.k.a. Dynamic (ENERGY!) Equilibrium (BALANCE!) -internal (inside) -external (outside) -Homeostasis -temperature -salt and water -glucose (simple sugar; C 6 H 12 O 6 ) -temperature -98.6°F -positive feedback=labor contractions!

4 hair up, vasoconstriction, shivering “ON” heat saved, heat made, blood warms “OFF”

5 hair down, vasodilation, sweating “ON” heat lost, blood cools “OFF”

6 insulin lowers carbohydrates glucose cellular respiration

7 What is hyperglycemia? Hyperglycemia (hi"per-gli-SE'me-ah) is an increase in plasma glucose (blood sugar). It can turn into a complex medical condition -- diabetic ketoacidosis (ke"to-as"id- O'sis) and coma -- if it's not treated on time and adequately. Hyperglycemia is usually the first sign of diabetes mellitus. Symptoms of hyperglycemia are polyuria (pol"e-YUR'e-ah) (excess urine) polydipsia (pol"e-DIP'se-ah) (thirst) polyphagia (pol"e-FA'je-ah) (excessive hunger)

8 What is hypoglycemia? Hypoglycemia (hi"po-gli-SE'me-ah) is a low level of plasma glucose (blood sugar). It's a dangerous condition because glucose is the major source of energy for the brain. Lack of glucose, like lack of oxygen, produces brain damage or even death if the deficit is prolonged. Hypoglycemia starts to cause these symptoms: sweating, tremors, anxiety, hunger, dizziness, headache, cloudy vision, confusion, abnormal behavior convulsions, loss of consciousness.

9 sugar uptake into cells, stored as glycogen “ON” (insulin released) normal blood sugar “OFF” (insulin stopped)

10 less ADH secreted, less urine “ON” water levels normal “OFF”

11 11 Enzymes: Who needs them? You do if you like detergents, bread, baby food, beer, fruit juice, cheese, candy, rubber, paper, or film because enzymes are needed to make these products! You do because living things can’t live without them and you, my friend, are a living thing.

12 12 A tasty and delicious example of an enzyme at work… Complex carbohydrates like starch and glycogen are broken down into the simple sugar a.k.a. monosaccharide glucose in your mouth with the help of the enzyme salivary amylase. I guess spit’s fantastic! A carbohydrate made of glucose subunits! Glucose, a simple sugar. salivary amylase

13 13 A not-so tasty and delicious example of an enzyme at work… The enzyme lactase, with the help of water, breaks (digests) the disaccharide lactose down into 2 monosaccharides─ galactose and glucose. Many adults, however, don’t make enough lactase so ingesting dairy causes symptoms like painful gas and diarrhea. Uh-oh!

14 14 Enzymes are everywhere! even in a bug’s butt luciferin + ATP oxyluciferin + AMP + light The above chemical equation represents a biochemical process that occurs in the abdomen of the firefly called bioluminescence. Without the enzyme luciferase to push the chemical reaction along, the insect would not glow and, therefore, would not be able to attract a mate. luciferase Photinus greeni finds a mate thanks, in part, to the enzyme luciferase!

15 15 How do enzymes keep us alive? An enzyme is a protein that catalyzes, or speeds up, a chemical reaction. Without enzymes, many of life’s vital biochemical processes would happen too slowly or not at all! Think about a little kid on a swing. Without a push, they aren’t going to get going. With a few pushes, though, that kid can swing on their own. The enzyme is what gives the biochemical process the push it needs to get going.

16 16 Enzymes are catalysts. Enzymes are biological catalysts. A catalyst makes a chemical reaction go faster but is not changed or used up by the reaction. The reason the enzyme’s name is written above the arrow in a chemical equation is because it is the only molecule not changed during the chemical reaction a.k.a. biochemical process. This means that the same enzyme can be used over and over again which saves the body energy because it doesn’t have to make new enzymes each time. Way to work smarter, not harder, body!

17 17 What’s a lock got to do with it? You have 1000s of enzymes in your cells and each one speeds up a different chemical reaction a.k.a. biochemical process. An enzyme’s shape determines what substrate it acts upon. This is called specificity and is illustrated by the lock-and-key model.

18 18 Enzymes: They Look a Hot Mess But They’re a Specific Shape Here is an image of the restriction endonuclease enzyme EcoRI which digests DNA. Here is an image of the enzyme lactase which digests milk sugar.

19 19 So what might an enzyme do during a chemical reaction? An enzyme grabs a substrate (the molecule that the enzyme changes) and breaks it apart. The active site is where enzyme and substrate connect. In this example, the name of the reactant is sucrose. The names of the products are glucose and fructose. This is a breakdown a.k.a. digestion reaction and it releases energy when bonds are broken!

20 20 Are digestion reactions the only type of reaction? No! There are also synthesis reactions where an enzyme makes a big molecule out of 2 smaller ones. This uses energy! CO 2 + H 2 O carbonic anhydrase Here’s a synthesis reaction taking place in your blood that happens 10 million times faster thanks to the enzyme:

21 21 How do enzymes speed up reaction rates and what affects them? Enzymes work by lowering the activation energy─ the amount of energy needed to push a chemical reaction forward. Each enzyme works best at a certain temperature, pH (acidic, neutral, or basic), and concentration (how much enzyme or substrate is around). Your body’s enzymes work best at normal body temperature and a neutral pH except for enzymes in the stomach and vagina which have adapted to an acidic environment.

22 22 Do enzymes always work? Sometimes high temperature or extreme pH (strong acids and bases) may affect the shape of an enzyme. This effect is called denaturation and can make the enzyme less effective and possibly useless. Just as a melted house key won’t open your door, a denatured enzyme won’t work on its substrate! Good luck maintaining homeostasis if that happens! It just may be the dun-dun-schnipple!


24 FOOD 1. Provides energy for all of the body’s functions, from the beating of the heart & the elimination of wastes to the transmission of electrical & chemical signals in the nervous system. Food is the fuel that contains energy from the sun, originally captured & stored by green plants, then passed along to fruits, seeds, & animals. Humans eat these foods & burn the fuel they contain to release the stored solar energy. As long as we live, we have to eat and eat often! Text from: Eating Well for Optimum Health Andrew Weil, MD

25 2. Food provides the building blocks of our bodies. In the same way that you can’t build a lego castle without lego pieces, you can’t build the parts of your body without certain nutrients.

26 The food we eat contains nutrients. Some of these we disassemble and then reassemble for parts we need. (Like breaking down the lego castle to build a lego ship instead.) Some nutrients are essential because we can’t manufacture these on our own. Macromolecules are these nutrients.Macromolecules come in 4 types. All macromolecules are organic which means they are produced and made by living things. Carbohydrates Lipids Proteins Nucleic acids

27 CARBOHYDRATES All carbs are made up of only 3 elements: Carbon, hydrogen, & oxygen. All carbs look like this in their simplest form. By the way, this is called a simple sugar or monosaccharide. mono = one saccharide = sugar But remember I said that you can use these guys as building blocks. Well if you put two of them together you get this. It’s called a disaccharide. Di = two

28 And if you string a bunch of monosaccharides together you get a polysaccharide. They look like this. Luckily they have the same general shape (hexagonal) and they are all carbohydrates.

29 WHY ARE CARBOHYDRATES IMPORTANT? They are the body’s preferred choice of energy. Just like your favorite shirt, you could wear the other shirt, but this one fits over your head without tugging. WHAT FOODS CONTAIN CARBOHYDRATES?

30 Let’s review carbohydrates. Why do you need to eat them? What foods contain carbs? List the 3 elements that are contained in carbohydrates. Which of the following is a polysaccharide?

31 LIPIDS Lipids contain 3 elements; carbon, hydrogen and oxygen.Sounds familiar right!

32 Fats are triglycerides which are solid at room temperature. Oils are liquid at room temperature. Why are lipids important to our bodies? 1.Storage of energy. This way if you run low on carbs….. 2. Thermal insulation. 3. Mechanical protection. Example surrounding delicate organs such as the heart. 4. Waterproofing. Like the wax in your ears.

33 Some fats are called phospholipids. They look like this. Basically, the difference is that instead of 3 fatty acids and one glycerol, they have 2 fatty acids and a glycerol. The also have an end that loves to be in water and a side that repels water. Two layers together is a perfect way to surround a cell or a cell part!

34 Also, by the way, some hormones are lipids. WHAT CAN YOU EAT TO MAKE SURE YOU HAVE LIPIDS? Butter

35 Review time. What 3 elements make up the group called lipids? Which of these are a lipid? How can you tell? List 3 ways your body uses lipids. What foods contain lipids?

36 PROTEINS Proteins are composed of 4 elements: carbon, hydrogen, oxygen and nitrogen. The basic unit is called an amino acid and it looks like this. This is a 3-D image of a protein containing thousands of amino acids connected together & folded to make this distinct shape.

37 WHY DO YOU NEED TO EAT PROTEINS? Proteins make up most of the structure of your body. Actually, by weight, you are mostly water with proteins in second place. These are muscle cells. This is someone with big muscles. Proteins can be enzymes; these proteins regulate chemical reactions in your body. Hair is also made up of protein.

38 Proteins also form some of the entrances and exits through the cell.


40 Review again? Of course!!!! 1. Which of the following suspects is a protein component? 2. List some foods that provide proteins? 3. How does my body use proteins?

41 NUCLEIC ACIDS Nucleic acids make up DNA and RNA which are gigantic molecules that carry your hereditary information from generation to generation and are used to make proteins (remember them). Nucleic acids are made up of lots of nucleotides (the smallest units) strung together. DNA takes the shape of a double helix. We will learn a lot more about nucleic acids later!!!!

42 Micronutrients are nutrients you need in small amounts. (That’s why they’re called micro. ) VITAMINS AND MINERALS All natural vitamins are organic food substances found only in living things. With few exceptions, our bodies can’t manufacture them. Many enzymes depend on vitamins to work properly. Minerals are inorganic substances such as calcium, iron, and salt that we need for such basic functions as muscles and nerves firing.

43 Dehydration is a lack of adequate body fluids for the body to carry on normal body functions. Fluid loss of 5% are considered mild, 10% moderate and up to 15% severe. Severe dehydration can result in cardiovascular collapse and death if not treated quickly. Symptoms: sunken eyes, dry or sticky mucus membranes in the mouth, skin lacks normal elasticity, decreased urination, decreased tears. WATER makes up more than half the weight of the human body. Without water, humans would die in a few days. All the cell and organ functions depend on water for functioning. It serves as a lubricant and forms the base for saliva and the fluids that surround the joints. It regulates the body temperature, as the cooling & heating are distributed through perspiration. Water helps to alleviate constipation by moving food through in the intestinal tract & thereby eliminate waste.


45 Kwashiorkor Meeting energy requirements is basic to survival A diet with excessive nonprotein calories from starch or sugar, but deficient in total protein and essential amino acids, results eventually in kwashiorkor. Kwashiorkor is characterized by generalized edema, "flaky paint' dermatosis, thinning and discolouration of the hair, enlarged fatty liver, and apathy in addition to retarded growth.

46 Symptoms: Weight loss of 25% or more, cold intolerance, constipation menstruation absent, skeletal muscle atrophy, low blood pressure, dental cavities, increased susceptibility to infection, blotchy or yellow skin, dry hair, hair loss and sometimes death. Anorexia nervosa is an eating disorder associated with a distorted body image. Inadequate calorie intake results in severe weight loss.

47 Cheese pizza diet causes scurvy in 5-year-old July 17, 2000 NEW YORK (Reuters Health) - When it was discovered that sailors away at sea could stop their gums from bleeding by sucking on a lime, one of the first links between disease--in this case, a vitamin C deficiency-- and diet became apparent. But a recent report illustrates that even modern-day children anchored at home are vulnerable to scurvy--a vitamin C deficiency that causes bleeding gums, loose teeth, muscle degeneration and weakness. In one case, a 5-year-old boy ate nothing but Pop-Tarts, cheese pizza, biscuits and water for 5 months, according to a report in the July issue of the Archives of Pediatrics and Adolescent Medicine. He refused fruits, vegetables, juices and vitamins. The result? A case of scurvy--a disease seldom seen in developed countries today.

48 While the boy was playful, alert and appeared to be growing normally, he developed a limp and was diagnosed with anemia. His gums became swollen and he developed small, purple spots on his skin. Eventually, the pain was so severe he was unable to get out of bed or walk without assistance. After ruling out leukemia or other ailments, the doctors diagnosed the youngster with a severe vitamin C deficiency, most likely caused by his unusual diet. The doctors gave the boy vitamin C, which improved his pain and symptoms within a week.




52 It is worth while studying this presentation thoroughly because it is essential for an understanding of all the activities of living cells and organisms 2 THE CONCEPT OF ‘RESPIRATION’ IS CENTRAL TO ALL LIVING PROCESSES

53 All living cells are made up of chemical substances The processes of living involve reactions between the substances A reaction is an event which produces a change in a substance For example, a reaction between carbon and oxygen (such as burning coal in air) changes the carbon in the coal, and oxygen in the air into carbon dioxide 3 This reaction can be represented by the equation C + O 2 CO 2 carbonoxygencarbon dioxide

54 C o o an atom of carbon c a molecule of oxygen O 2 combine to form a molecule of carbon dioxide CO 2 plus 4

55 The reaction between carbon and oxygen also releases energy in the form of heat and light (flames) Living organisms get their energy from reactions like this (but not reactions which are violent enough to produce flames) 5

56 energy release source of carbon oxygen CO 2 6

57 7 One of the energy-producing reactions is called respiration (Respiration is not the same thing as breathing) The chemical reactions of respiration take place in all living cells The reaction takes place between oxygen and a substance which contains carbon. The reaction produces carbon dioxide and water, and releases energy

58 The carbon-containing substances come from FOOD The oxygen comes from the AIR (or water) The energy is used to drive other chemical reactions taking place in cells One example of this is the release of energy in muscle cells to make them contract and produce movement 8

59 9 One example of an energy-producing reaction in cells is the breakdown of sugar when it combines with oxygen This can be represented by the equation C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O +energy sugar (glucose) oxygencarbon dioxide water This means that one molecule of sugar reacts with six molecules of oxygen to produce six molecules of carbon dioxide and six molecules of water. Energy is released during this process

60 Respiration supplies the energy for muscle contraction germination cell division chemical changes in cells Some examples of the use of energy in organisms 10

61 The blood stream brings food and oxygen to the muscle cells. Respiration occurs in the cells and releases energy which…… shoulder blade upper arm bone lower arm bones Energy use in muscle contraction 11

62 12 …….makes the muscle contract and pull the lower arm up

63 (a) (b) (a) is a section cut through the length of a maize seedling. Areas of rapid respiration are stained pink. (b) and (c) are drawings of the seed and the seedling that grows from it. Can you suggest reasons why respiration should be so rapid in the stained regions? embryo shoot embryo root food store 13 root (c) shoot root

64 Answer The most intensely stained areas are in the root tip and the shoot tip. These are regions where very rapid cell division is taking place to produce growth. Making new cells and new cytoplasm takes a great deal of energy. You might also have noticed that, in the root, there are two faint streaks of pink. These occur in the conducting tissue of the seedling. Energy is needed to transport food from the food store to the growing region. 14

65 Glucose and oxygen react to produce energy for muscle contraction 4 RESPIRATION 5 Carbon dioxide is carried to the lungs by the blood 15 One example of respiration in ourselves 1. Air taken in 1.Food taken in 2. The lungs absorb oxygen from the air 2.The stomach and intestine digest food. One of the products is glucose 3.The blood stream carries glucose and oxygen to the muscles

66 Anaerobic Respiration 23

67 The process of respiration described so far has been defined as the release of energy when foodstuffs such as glucose react with oxygen to produce carbon dioxide and water. This form of respiration, which needs oxygen, is called aerobic respiration. There is another form of respiration which does not need oxygen and is called anaerobic respiration. In anaerobic respiration, glucose is still broken down to carbon dioxide with the release of energy, but without the involvement of oxygen The glucose is not completely broken down to CO 2 and H 2 O but to CO 2 and alcohol (ethanol). 24

68 Anaerobic respiration can be represented by the equation C 6 H 12 O 6 2C 2 H 5 OH + 2CO 2 glucose alcohol energy For example, our own muscles resort to anaerobic respiration when oxygen is not delivered to them fast enough. The energy released by anaerobic respiration is considerably less than the energy from aerobic respiration. Anaerobic respiration takes place at some stage in the cells of most living organisms. 25

69 Micro-organisms Anaerobic respiration is widely used by many micro-organisms such as bacteria and yeasts. Bacteria and yeasts are microscopic single-celled organisms. Bacteria are to be found everywhere, in or on organisms, in water, air and soil Yeasts are usually found in close association with vegetable matter such as fruit 26

70 Bacteria 0.002mm a single bacterium there are many species of bacteria and they have different shapes and sizes cell wall nucleus cytoplasm 27

71 Aerobic and anaerobic bacteria Bacteria which need oxygen in order to respire are called aerobic bacteria. Aerobic bacteria are likely to be found in the air, water and soil where oxygen is available Bacteria which can respire without needing oxygen are called anaerobic bacteria Anaerobic bacteria are to be found in situations where oxygen is lacking, such as in stagnant water, waterlogged soils or the intestines of animals 28

72 Fermentation One form of anaerobic respiration in bacteria and yeasts is called fermentation. During fermentation, sugar is broken down to alcohol and carbon dioxide The reaction described in slide 25 is an example of fermentation Fermentation is involved in brewing and wine-making 30

73 Yeasts 0.005mm single yeast cell Yeast cells dividing cell wall nucleus cytoplasm vacuole 29

74 Baking In baking, yeast is added to a mixture of flour and water, made into the form of a dough The yeast first changes the flour starch into sugar and then ferments the sugar into alcohol and CO 2 The CO 2 forms bubbles in the dough which cause it to expand (‘rise’) When the dough is baked, the heat evaporates the alcohol but makes the trapped bubbles expand giving the bread a ‘light’ texture 35

75 Dough rising 36 The yeast is mixed with the dough After 1 hour in a warm place the dough has risen as a result of the carbon dioxide produced by the yeast

76 The ‘holes’ in the bread are made by the carbon dioxide bubbles. This gives the bread a ‘light’ texture 37

77 1. What does the tubing represent? 2. What is inside the tubing? Cell membrane Starch & glucose

78 3. What did we add to make the liquid outside the “cell” amber colored? Starch indicator (iodine aka Lugol’s Solution)

79 4. Why does the inside of the “cell” turn purple or black? Starch indicator diffused into the tubing High s.i.conc. Low s.i. conc.

80 5. How do we know that starch did not move from the inside to the outside? No color change outside. If there was starch in the beaker water, it would be purple!

81 6. How can we find out if glucose moved into the beaker? Glucose (high conc.) ? Do a glucose indicator test using the fluid in the beaker

82 7. After placing 10 drops of the amber solution into a test tube, what do we add to it? Glucose indicator aka Benedict’s Solution

83 8. After adding the glucose indicator solution (blue) what do we do with the test tube? Heat it

84 9. If there is glucose in the solution, what will happen to the blue color after heating the tube for 2 minutes? The color changes

85 10. The blue color changed to orange. This means that what substance is in the test tube? Glucose

86 11. Glucose indicator solution was added to these test tubes, and then the tubes were heated. Which will change color? starch glucose C 6 H 12 O 6 What is this?? (hint: “plants”)

87 Were you right?

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