8 LIFE PROCESSES NUTRITION TRANSPORT REGULATION SYNTHESIS EXCRETION GROWTH REPRODUCTION RESPIRATION

Transcription

1 8 LIFE PROCESSES NUTRITION REGULATION EXCRETION REPRODUCTION TRANSPORT SYNTHESIS GROWTH RESPIRATION

2 LIFE PROCESSES Nutrition (ingestion, digestion, egestion) 1- Nutrients are used by all living things for energy, and as raw materials for growth and repair. 2- Nutrients are broken down into a form that can be absorbed and used by cells. Transport 1- Transport involves the absorption and circulation of needed materials throughout an organism. 2- Circulatory Systems

3 Respiration (THINK ENERGY!) 1- Respiration is the release of energy from food in a complex series of chemical reactions within a cell. 2- Breathing, a part of respiration, is the movement of air into and out of an animals lungs- respiration is the release of energy from food (nutrients). Synthesis and Assimilation 1- Assimilation is how an organism incorporates (uses) nutrients into the body 2- Synthesis is the process that combines small/simple molecules to form larger more complex molecules

4 Growth 1- Organisms grow by synthesizing new cells (tissues) using the nutrients they have taken in. 2- The raw materials for growth are either ingested (eaten) or produced by the organism (photosynthesis). Excretion 1- Excretion is the removal of metabolic wastes from the body. NOT removal of solid waste 2- Complex organisms must have a way to remove harmful (metabolic) wastes from the cells and eliminate them.

5 Regulation The control and coordination of all life activities 1- Electrical. (nervous system) 2- Hormones (endocrine system) Reproduction An organisms ability to reproduce itself, or make new cell, for repair and growth

6 Unity of Life Despite large differences in appearance and ways of life, all living things have something in common. ALL LIVING THINGS ARE COMPOSED OF ONE OR MORE CELLS!!!

7 The Cell Theory 1- The cell is the unit of structure and function of plants and animals. (Plants and animals are composed of cells and cell products made by cells). 2- The cell is the smallest unit having the properties of Life 3- All cells arise from preexisting cells. 4- Viruses are the only exception to this theory. Viruses are not technically alive and require a living host to reproduce.

8 If all cells come from preexisting cells, then where did the first cell come from? Which came first, the chicken or the egg?

9 How do scientists solve problems? Scientific methods a model or a guide that scientists use to approach problems (7 steps). Step 1. Identify & State the Problem (make an observation) State problem as a question Step 2. Research the Problem (question) use all available resources to collect data on subject being covered (libraries, internet, books, magazines, etc.)

10 Scientific methods continued. Step 3. State a Hypothesis (educated guess) State clearly what they expect to find out a suggested solution to a problem based upon known information Step 4. Design an Experiment (used to test the hypothesis) Variable is the thing being tested often comapre to. Control - constant

11 Scientific Methods continued. Step 5 Make Observations & Record Data (measurements or #s) Step 6 Organize & Analyze Data use graphs, charts, tables, diagrams then analyze and study data to see if they support hypothesis Step 7 State a Conclusion conclusion may or may not support hypothesis if hypothesis is proven wrong change the hypothesis not the data

12 Technique for Constructing a Line Graph 1. Identify the variables to be plotted independent variable -- the variable manipulated by the experimenter -- is plotted on the x-axis (horizontal axis) dependent variable -- the factor responding to changes in the independent variable -- is plotted on the y-axis (vertical axis)

13 2. Determine the scale of the axes -- determine each axis individually -- may easily be determined by taking the largest value to be plotted and dividing by the number of blocks and then rounding up to the nearest convenient number -- the graph should be spread to occupy the most available space 3. Number and label each axis indicating the appropriate units. 4. Plot each data value on the graph with a point.

14 5. Draw a line that best fits the data points. -- do not connect data points to the origin unless there is data to support this -- if possible, do the graph of experimental data as a "best fit" line for the points which have been plotted. 6. Provide a title which clearly indicates what the graph is about. 7. If the graph has more than one set of data, provide a key to indicate what is represented by the different lines.

15 A scientist conducted an experiment to test the hypothesis that maple seeds exposed to acid rain will take longer to germinate than seeds exposed to normal rain, which has a ph of 5.6. The scientist set up four groups, each containing 200 maple seeds. The water used for each group had a different ph value: 5.6, 4.0, 3.0, and 2.0. All other conditions were kept the same. After ten days, the number of seeds that had germinated in each group was counted. Identify the control group in this experiment. Identify the dependent variable in this experiment.

16 ph SCALE measures degree of substance alkalinity or acidity Ranges from 0 to strong acid 6-7 neutral 8-14 strong base

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18 Organic Molecules Organic Molecules - contain BOTH carbon and hydrogen atoms together in some ratio. There are 4 classes of organic molecules found in living things: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

19 Large organic food molecules such as proteins and starches must initially be broken down through the process of digestion in order to enter cells. Organic Molecule Carbohydrates Proteins Lipids (fats) Digestive End Products Simple sugars (glucose) Amino acids Fatty acids and glycerol

20 Which substances are the most commonly used as building blocks in the synthesis of some lipids? 1. sugars and starches 2. amino acids and nucleotides 3. glycerol and fatty acids 4. starches and enzymes

21 Chemical Control Billions of chemical reactions occur in living organisms every second. Each reaction is controlled so that it proceeds at the right speed and at the right time. Organic compounds called enzymes are responsible for this control.

22 3. Catalysts Catalyst a chemical substance that can speed up the rate of a chemical reaction without being used up itself. Catalysts are used in living things. Catalysts that function in living things are called ENZYMES Enzymes help lower the activation energy of a reaction.

23 Enzyme Action Enzymes are very specific and will only do a very specific job. The molecules that enzymes act upon are called substrates. The unique shapes of enzymes allow them to fit closely with particular kinds of substrate molecules, just like a lock and key.

24 Substrates will join with an enzyme at a specific place on the enzyme molecule called the active site. It is important to remember the enzymes are VERY SPECIFIC a term known as enzyme specificity.

25 After the products are set free, the enzyme can attach itself to another substrate and repeat the process. ENZYMES ARE NOT USED UP!!!

26 Factors Influencing Enzyme Activity

27 Temperature: strongly influences enzyme activity optimum (best) temperature for maximum enzyme function is usually about C. reactions proceed slowly below optimal temperatures above 45 C. most enzymes are denatured (change in their shape so the enzyme active site no longer fits with the substrate and the enzyme can't function)

28 Temperature The optimum temperatures for enzyme action vary with the type of organism. Human enzymes function best at 37 degrees Celsius and plant enzymes function best at 25 degrees Celsius.

29 What happens when the temperatures get too high? If proteins are exposed to extreme conditions, they lose their characteristic shape in a process called denaturation. The active sites are altered and the enzyme is unable to perform its function. Once an enzyme is denatured, it is impossible to restore it to its normal condition.

30 Factors Influencing Enzyme Activity ph: the optimum (best) in most living things is close to 7 (neutral). High or low ph levels usually slow enzyme activity

31 ph The ph at which specific enzymes react best with their substrates is called the optimum ph. Enzymes quickly lose their effectiveness when the ph goes even a little above or below the optimum. Optimum ph for enzymes is around 1.5 and 8

32 Nutrients are used by all living things for energy, and as raw materials for growth and repair. Organisms that are able to manufacture organic nutrients from substances in the abiotic environment are classified as (1) heterotrophs (3) predators (2) fungi (4) autotrophs

33 The overall process of photosynthesis in a plant or algal cell is shown in the graphic below. Plants use use water and the energy provided by sunlight to combine carbon dioxide into glucose sugar with oxygen being released as a waste product.

34 What is Photosynthesis? CO 2 + HOH > Glucose + O 2 + HOH Light energy Chlorophyll Enzymes

35 In the leaf of a plant, guard cells help to (1) destroy atmospheric pollutants when they enter the plant (2) regulate oxygen and carbon dioxide levels (3) transport excess glucose to the roots (4) block harmful ultraviolet rays that can disrupt chlorophyll production

36 Photosynthesis is The capture of light energy and its conversion to chemical energy in organic molecules. Photosynthesis occurs in cells called chloroplasts that contain the green pigment chlorophyll.

37 Describe the cycling of carbon in an ecosystem. In your answer be sure to: identify the inorganic carbon compound that is obtained by plants from the environment [1] identify the process plants use to form more complex organic molecules from this carbon compound [1] describe how herbivores use these complex organic molecules [1] identify the process herbivores use to return carbon to the environment [1]

38 Carbon dioxide makes up less than 1 percent of Earth s atmosphere, and oxygen makes up about 20 percent. These percentages are maintained most directly by (1) respiration and photosynthesis (2) the ozone shield (3) synthesis and digestion (4) energy recycling in ecosystems

39 Cell Membrane Surrounds the cell Controls what enters and leaves the cell (selectively permeable) Contain receptor molecules to communicate with other cells.

40 Transport ISOTONIC SOLUTIONS

41 HYPOTONIC SOLUTIONS

42 HYPERTONIC SOLUTIONS

43 Transport Describe what will happen to red onion cells in a wet-mount slide when a saltwater solution is added to them.

44 Which organ system in humans is most directly involved in the transport of oxygen? (1) digestive (3) excretory (2) nervous (4) circulatory

45 The virus that causes AIDS is damaging to the body because it (1) targets cells that fight invading microbes (2) attacks specific red blood cells (3) causes an abnormally high insulin level (4) prevents the normal transmission of nerve impulses

46 CHEMISTRY OF CELLULAR RESPIRATION In Anaerobic respiration, (without oxygen) glucose is converted to pyruvate which is then converted to lactic acid or alcohol (ethanol). Remember, the net gain of anaerobic respiration is only 2 ATP. (That s like getting two miles/gallon) 2 ATP are used to start the reaction and four ATP are produced. The overall equation is 2 ATP (consumed) 4 ATP produced = 2 ATP total

47 An excellent example of an ideal respiratory surface is the inside of the human lung.

48 Diffusion and Osmosis Designed to help you understand the concepts of Diffusion and Osmosis and how these cell processes effect the cell; Define: diffusion, osmosis, hypertonic, isotonic, hypotonic, saline, selectively permeable, molecule size;

49 Part 1: Diffusion Diffusion: movement of molecules from an area of high concentration to an area of low concentration along the concentration gradient. Example is when you put your Lugol s solution into the water and the water began to turn the rust/tea color.

50 Part 2: Create a cell Soak 10 inches of dialysis tubing; Tie knot in one end; Put 10mL of glucose solution in and 20mL of starch solution in; Pinch/clamp closed and put into cellular environment (Lugol s and water) for 15 minutes; Observe the changes and infer what happened Insert into cellular environment Wait about 15 minutes and observe.

51 After 15 minutes, observe What happened to the glucose in the cell? the starch in the cell? the Lugol s iodine outside the cell? Why? I I G G S G S I I G I G I S I S G I Iodine solution (I) Glucose solution (G) Starch solution (S)

52 And now, the part that makes you cry (ok, not really, but the Red Onion part of the lab) Prepare a wet mount slide of the inner epidermis of a red onion section; Observe the red onion and draw what you see; Add a couple of drops of saline (salt) solution to the epidermis. Wait 5 minutes; Observe under microscope again, note any changes; Add freshwater to the slide, wait 5 minutes, observe changes again.

53 Red Onion Plasmolysis Observation Before and after observations of red onion epidermis under the microscope (400X) Red onion under in isotonic (normal) solution. Note cell membrane and cytoplasm almost completely fill the boundary of the cell wall. Red onion under in hypertonic (salt) solution. Note cell membrane has withdrawn and the cytoplasm has lost water to the salty environment, making it appear smaller and darker.