Life’s Organization Unit 2

1. Life’s OrganizationUnit 2 Yes, it is time to move to your second divider labeled Unit 2

2. What makes something alive? • To be considered alive, an organism (living thing) must have certain characteristics.

3. 1. Be made up of Cells • Living things (Organisms) are made up of small, contained units called cells. • Cells are the smallest unit of an organism. • Organisms can be unicellular or consist of one cell. (We’ve seen these in the pond water lab) • Many living things are multicellular which means many cells. Plants and most animals are multicellular.

4. 2. Living Things (Organisms) Reproduce • All organisms produce new organisms through the process of reproduction. • There are two types of reproduction sexual and asexual. • Sexual reproductioninvolves two different parents that each provide a cell (gamete) to produce an offspring

5. Asexual reproduction involves one parent. Usually the offspring splits off from its parents. For example a cell splitting in two. The offspring has the exact same genetics as its parent.

6. 3. Organisms are put together based on their Genetic Code • All organisms are based on a universal genetic code know as deoxyribonucleic acid also known as DNA. • In asexual reproduction, the offspring have the same exact genetic code. The offspring are clones of their parent. • In sexual reproduction, offspring share some characteristics of each parent. Offspring DNA is 50% from Mother and 50% from Father.

7. 4. Organisms Grow & Develop • All living things grow at some part of their lives. Growthis an increase in cell size or cell number • Growth takes place when a fertilized egg cell divides many times • Cell differentiation results in some cells becoming specialized as bone cells, liver cells or brain cells • Development can also include periods of rapid change – in humans aka puberty!!

8. 5. Organisms need materials & energy • Living Things need food for energy to grow, reproduce and survive. • Metabolisminvolves the chemical reactions that organisms do to break down and build materials needed to carry out life functions and stay alive. • The way living things get their energy varies. Autotrophs/Producers make their own food using the sun’s energy through photosynthesis.

9. Heterotrophs/Consumers get their energy by eating other organisms. Herbivores -eat primarily plants Carnivores eat primarily meat Omnivores eat both meat & plants Decomposers- are mostly fungi and bacterial that consume dead plants & animals

10. 6. Organisms Respond to their Environment • Living things are aware of and respond to stimuli in the environment. • A stimulus is a signal that an organism responds to. • External stimuli comes from the environment such as changes in light, temperature, noise, etc. • Internal stimuli comes from inside the organisms body. When your body’s blood glucose (sugar) falls too low, you become hungry.

11. 7. Living Things maintain an Internal Balance • Homeostasis- involves processes that an organism uses to keep internal conditions (like temperature & water constant) stable & constant to survive. • Homeostasis involves internal feedback systems in our bodies. If our body temperature gets too hot when exercising, our skin sweats to help to cool us down. If our temperature gets too cold we shiver to produce heat in our body.

12. 8. Living things excrete waste products • Excretion is the process by which waste products of metabolismand other non-useful materials are eliminated from an organism • Humans excrete urine which is concentrated in the kidneys • Fish and water organisms excrete Ammonia which is highly toxic and highly soluble in water

13. 9. Some living things can move • Movement- The ability to move is called locomotion. This is beneficial to an organism in allowing it to escape predators, move to where there is more food or to find mates. Cilia Flagella Setae or hairs on an earthworm Water Flea AKA Daphne

14. 10. Living Things conduct Synthesis • Synthesis-the process that organisms take simple building blocks and make something more complex • Plants synthesize glucose using sunlight, CO2 and water.

15. 11. Living Things can Evolve • Over time organisms change in response to changes in the environment. The change may be gradual and take many generations. • Evolution is the change in a species over time responding to changes in their environment.

18. Structural Organization of Organisms • Organism-an individual with the ability to carry out the activities of life • Organ Systems-A group of organs that work together to perform a major task (i.e. digestive systems, reproductive system) • Organs-a Structure made up of similar tissues that work together to perform a task. Often part of a larger system. (i.e. stomach, eyes, kidneys

19. Tissues- A group of similar cells that work together to perform the same function (i.e. muscle tissue) • Cells-Smallest living unit of an organism

20. Cellsare the basic unit of structure in every living thing. • New cells are formed from other existing cells • The cell is a fundamental unit of structure, function and organization in all living organisms. Cell Theory–Developed during the mid 17th century was made possible by advances in microscopy. Cells theory states that:

22. Many scientist do not classify viruses with living things • Viruses are not made of cells • Virusesare made of proteins and genetic material HIV Virus

23. Viruses cannot independently carry out all of the processes of life (can’t function outside of a living cell) • Virus must invade the cell of a living organism to reproduce • Some viruses are pathogens. Pathogens are anything that causes disease. • Virus also do not respond to antibiotics • Different Viruses cause HIV, influenza, warts and many other diseases

24. Prokaryote- cells that don’t have a nucleus or many organelles • Came first-were the first examples of life • Simple compared to eukaryote cells • Prokaryotes-Think of bacteria which can be killed using antibiotics. There are two types of cells

25. Eukaryotes- are more complex and are what you are used to seeing and studying. • Have a nucleus that contains the genetic information • Have many specialized organelles

27. Eukaryote CELLS and Cell Organelles

30. Cytoplasm refers to the jelly-like material with organelles in it. AKA CytosolIf the organelles were removed, the soluble part that would be left is called the cytosol. It consists mainly of water with dissolved substances such as amino acids in it.

31. Nucleus- The nucleus is the control center of the cell. It is the largest organelle in the cell and it contains the DNA of the cell. DNA (Deoxyribonucleic Acid) contains all the information for cells to live, perform their functions and reproduce.  Inside the nucleus is another organelle called the nucleolus. The nucleolus is responsible for making ribosomes.

32. Mitochondria • Mitochondria-Their main function is the conversion of the potential energy of food molecules into ATP. • There are more mitochondria in cells that have to perform lots of work (leg muscle cells, heart muscle cells etc). • Mitochondria have their own DNA • Mitochondrial DNA- You have an exact copy of your mother’s mitochondrial DNA

33. Mitochondria have: • an outer membrane that encloses the entire structure • an inner membrane that encloses a fluid-filled matrix • between the two is the intermembrane space

34. Cellular Respiration takes place in the Mitochondria All living cells do cellular respiration

35. Endoplasmic reticulum (ER)- The rough endoplasmic reticulum is where most protein synthesis occurs in the cell. There are two types of ER. • Rough ER- When ribosomes are attached it • Smooth ER when there are no ribosomes attached. 

36. Golgi complex- It is organelle in the cell that is responsible for sorting and correctly shipping the proteins produced in the ER.  Just like our postal packages which should have a correct shipping address, the proteins produced in the ER, should be correctly sent to their respective address.  In the cell, shipping and sorting done by the Golgi complex. It is a very important step in protein synthesis (Making of Proteins). .

37. Some ribosomes are found in the cytoplasm, but most are attached to the endoplasmic reticulum. • Ribosomes- Organelles that help in the synthesis of proteins.

38. The fluid mosaic model describes the structure of the plasma membrane • The Fluid-mosaic model- membrane is seen as a bilayer of phospholipids in which protein molecules are embedded.

39. Channels/pores- A channel in the cell's plasma membrane. This channel is made up of certain proteins whose function is to control the movement of food and water into the cell. These channels are made up of certain proteins.

40. Vesicles- This term literally means "small vessel". This organelle helps store and transport products produced by the cell. The vesicles are the transport and delivery vehicles like our mail and  Federal Express trucks. Some vesicles deliver materials to parts of the cell and others transport materials outside the cell in a process called exocytosis

41. Lysosomes function as the cell's recycling compartment. Lysosomes receive cellular and proteins and lipids that need digesting through the process of endocytosis. The metabolites that result are transported either by vesicles or directly across the membrane.

42. CENTROSOME A Centrosome is found in the nucleus and is made of a pair of small Organelles called the centrioles. Centrioles are made up of a ring of nine groups of microtubules. During animal cell division, the centrosome divides and the centrioles replicate (make new copies). The two centrosomes move to opposite ends of the nucleus, and from each centrosome, microtubules grow into a "spindle" which is responsible for separating replicated chromosomes into the two daughter cells. Plant cells have centrosomes that function much like animal cell centrosomes. However, unlike centrosomes in animal cells, Plant cells do not have centrioles.

43. Vacuoles- can be used to store water, waste or food inside of a plant cell. • Vacuoles and vesicles are storage organelles in cells. Vacuoles are larger than vesicles. Either structure may store water, waste products, food, and other cellular materials.

44. In plant cells, the vacuole may take up most of the cell's volume. When a plant wilts it means that the vacuole has lost enough water so the “water balloon” deflates and no longer helps the cell wall hold the plant upright.

45. Chloroplast-The cell organelle in which photosynthesis takes place. In this organelle the light energy of the sun is converted into chemical energy. - Chloroplasts are found only in plant cells not animal cells. -Chloroplasts contain tiny green pigments called chlorophylls - Chlorophyllsare responsible for trapping the light energy from the sun.

46. The chemical energy that is produced by chloroplasts is finally used to make  glucose and carbohydrates like starch

47. PHOTOSYNTHESIS GLUCOSE Organic (comes from something alive) molecules contain Carbon and Hydrogen

48. Cell Wall- One of the most important distinguishing features of plant cells is • the presence of a cell wall • The cell wall protects the cellular contents gives rigidity to the plant structure • The cell wall is a structure of great tensile strength, the cell wall is formed from fibrils of cellulose molecules • Animal cells do not have • a Cell wall.

49. Photosynthesis is the reverse reaction of Cellular Respiration