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6.1 All organisms are made of cells

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6.1 All organisms are made of cells. I. The Cell Theory A.In 1655 Robert Hooke observedcompartments in a thin slice of cork which he named cells B.In.

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1 6.1 All organisms are made of cells

2 I. The Cell Theory In 1655 Robert Hooke observed “compartments” in a thin slice of cork which he named cells In 1700 Anton van Leeuwenhoek had developed light microscopes to observe tiny living organisms which he named “animalcules”

3 First microscopes

4 The Cell Theory C. Cell theory is the generalization that all living things are composed of cells, and that cells are the basic unit of structure and function in living things

5 II. Microscopes as Windows to Cells
Light microscopes can magnify objects up to about 1,000 X Electron microscopes can magnify objects up to about 1,000,000 X C. A photograph of the view taken through a microscope is called a micrograph

6 Microscopes

7 Microscopes SEM- scanning electron microscope TEM- transmission
Both must use preserved specimens.

8 Microscopes

9 III. An Overview of Animal and Plant Cells
Each part of a cell with a specific job to do is called an organelle B. The plasma membrane defines the boundary of the cell and regulates traffic in and out of the cell

10 Overview of animal and plant
The nucleus stores the genetic material of the cell D. The region of the cell between the nucleus and the plasma membrane is called the cytoplasm

11 Animal Cell

12 Animal Cell

13 Plant cell

14 Plant cell

15 IV. Two Major Classes of Cells
A prokaryotic cell lacks a nucleus and most other organelles B. A eukaryotic cell has a membrane bound nucleus and organelles

16 Animal v. Plants Animal Plant Plasma membrane Membrane and cell wall
Mitochondria Mitochondria and chloroplast Cytoplasm, nucleus Both Most organelles

17 Eukaryotic v. Prokaryotic
Nucleus No nucleus Plants and animals Bacteria Cytoplasm Organelles Lacks organelles

18 6.2 Membranes organize a cell’s activities

19 I. Membrane Structure Membranes regulate the transport of substances across it Membranes are composed mostly of proteins and phospholipids

20 Membrane structure The phospholipids form a two-layer sandwich called a “phospholipid bilayer” which surrounds the organelle or cell D. The membranes are fluid-like rather than sheets of molecules locked rigidly into place

21 Plasma membrane

22 Plasma membrane

23 II. The Many Functions of Membrane Proteins
Many types of proteins are embedded in the membranes phospholipid bilayer B. Some proteins carry out some of the cells important chemical reactions, others helps cell communicate and recognize each other, other proteins move substances like sugar and water across the membrane

24 Functions of Membrane Proteins

25 6.3 Membranes regulate the traffic of molecules

26 I. Diffusion Diffusion is the net movement of the particles of a substance from where they are more concentrated to where they are less concentrated B. Equilibrium is reached when the movement of particles in one direction is equal to the number of particles moving in the other

27 Diffusion

28 II. Passive Transport A selectively permeable membrane allows some substances to cross the membrane more easily than others and blocks the passage of some substances altogether

29 Passive transport Diffusion across a membrane is called passive transport because no energy is expended by the cell, only the random motion of molecules is required to move them across C. Facilitated diffusion is when transport proteins provide a pathway for certain molecules to pass

30 Passive transport Carbon dioxide, oxygen- nonpolar
Water, glucose - polar molecules

31 III. Osmosis The passive transport of water across a selectively permeable membrane is called osmosis A solution with a higher concentration of solute is called hypertonic hyper = “above” C. A solution with a lower concentration of solute is called hypotonic hypo = “below”

32 III. Osmosis D. A solution that has an equal concentration of solute is called isotonic iso = “equal” When an animal cell is placed in a hypotonic solution it swells - When an animal cell is placed in a hypertonic solution it shrinks

33 Osmosis

34 IV. Active Transport When a cell expends energy to move molecules or ions across a membrane it is called active transport B. A specific transport protein pumps a solute across a membrane, usually in the opposite direction it travels in diffusion

35 Active Transport Sodium / potassium pump

36 V. Transport of Large Molecules
Large molecules have to be packed into vesicles, which are small membrane sacs that specialize in moving products into, out of and within a cell

37 Transport of large molecules
When a cell exports its protein products, a vesicle fuses with the plasma membrane and spills its contents outside the cell-a process called exocytosis The reverse process, endocytosis, takes materials into the cell within vesicles that bud inward from the plasma membrane

38 Transport of large molecules

39 6.4 The cell builds a diversity of products

40 I. Structure and Function of the Nucleus
A. The nucleus in a cell contains DNA which controls all of the activities inside the cell B. The nucleus is surrounded by the nuclear envelope which has hole in it which allow substances to pass in and out of the nucleus C. Inside the nucleus is the nucleolus which contains parts necessary to make ribosomes

41 nucleus

42 II. Ribosomes DNA codes for the production of proteins which are made in the ribosomes B. The ribosomes are either bound to the surface of the endoplasmic reticulum or suspended in the cytoplasm

43 III. The Endoplasmic Reticulum
The endoplasmic reticulum is an extensive network of membranes which functions as the main manufacturing and transportation facility in the cell 1. Rough ER-The rough ER has ribosomes which insert proteins right into or through the ER membrane or packaged in vesicles and transported outside the cell

44 Endoplasmic Reticulum
2. Smooth ER-The smooth ER lacks ribosomes but enzymes in the smooth ER allow it to make lipid molecules

45 IV. The Golgi Apparatus A. The golgi apparatus receives products from the ER and modifies, stores and routes proteins and other products to their final destination B. This organelle is analogous to a processing a shipping center of the cell

46 V. Vacuoles The cytoplasm has large, membrane bound sacs called vacuoles B. Some vacuoles contain undigested nutrients, some pump out excess water that diffuses into a cell, others store chemicals that contribute to cell growth

47 VI. Lysosomes Membrane bound sacs called lysosomes contain digestive enzymes that can break down such molecules like proteins, nucleic acids and polysaccharides B. Lysosomes will digest food, destroy bacteria and digest damaged organelles

48 V. Membrane Pathways in a cell
The membranes inside a cell are transferable from one organelle to another B. Products may leave a cell without ever crossing a membrane

49 Membrane pathway in a cell

50 6.5 Chloroplasts and mitochondria energize cells

51 I. Chloroplasts Chloroplasts are the photosynthetic organelles found in some cells of plants and algae Photosynthesis is a complex, multi-step process and the chloroplasts provides the necessary organization for the process to take place C. Inside the chloroplasts are disks that act as the “power pack”

52 chloroplasts Chloroplasts are the photosynthetic organelles found in some cells of plants and algae Photosynthesis is a complex, multi-step process and the chloroplasts provides the necessary organization for the process to take place C. Inside the chloroplasts are disks that act as the “power pack”

53 II. Mitochondria A. Mitochondria are structures where cellular respiration occurs, a process that most organisms use to access energy ATP is the main energy source for the cell and is the end result of cellular respiration C. Mitochondria have many infoldings which allows for a larger surface area which results in more sites for respiration to take place

54 mitochondria

55 6.6 An internal skeleton supports the cell and enables movement

56 I. The Cytoskeleton Straight hollow tubes of proteins that give rigidity, shape and organization to a cell are called microtubules B. Thin solid rods of protein that enable the cell to move or change shape are called microfilaments

57 microtubules & microfilaments

58 II. Flagella and Cilia Flagella are long, thin whip-like structures with a core of microtubules that enables the cell to move B. Cilia are generally shorter and more numerous than flagella and move back and forth and moves a cell

59 flagella and cilia

60 III.The Cell as a Coordinated Unit
It is important to remember that a cell’s organelles do not work alone B. The structure of a cell and its organelles determine its function and all the individual parts must work together

61 SA 2 ( 4 pts total) Draw a single cell. Label the nucleus.
Is this a plant or animal cell - how do you know?

62 Bonus (4 pts) Draw one organism. Label any visible structures.
What are the structures used for?

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