Ask yourself. Chapter 3 Cell Structure and Function. Examples of Cells. A is cell the smallest unit that is capable of performing life functions.

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1 Chapter 3 Cell Structure and Function Ask yourself If you were a scientist living in the 1500s, what kind of questions would you ask yourself if you were the one to discover cells? Let me think. Cell Video A is cell the smallest unit that is capable of performing life functions. Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell 1

2 Section 3.1 Cell Theory History of Cell Theory The cell theory grew out of the work of many scientists and improvements in the microscope Robert Hooke Observed cork under a microscope. Noticed it was made of tiny compartments that reminded him of small rooms found in monasteries so he gave them the same name- cells The cells were actually dead and only the cell walls remained. The Cell Theory 1. All organism are made of one or more cells. 2. The cell is the most basic unit of life. 3. All existing cells are produced by other living cells. 2

3 Two Types of Cells Eukaryotic Prokaryotic Two Types of Cells: Prokaryotic and Eukaryotic Eukaryotic cells True membrane bound nucleus and organelles. Contain a nucleus Ex. plant and animal, fungi Prokaryotic cells Do not have a membrane-bound nucleus or organelles. It has a cell wall Ex: Bacteria Bacteria organelles Cell Wall Plants and Animals Two Types of Cells: Prokaryotic and Eukaryotic Similarities Cell membrane Cytoplasm DNA Ribosomes nucleus Differences Prokaryotic and Eukaryotic Cells DNA cytoplasm cell membrane DNA cytoplasm 3

4 Prokaryotic vs Eukaryotic Section 3.2 Cell Organelles Single-Cellular Nucleus Simple Cytoplasm Membrane Bound Organelles Bacteria Fungi Multi-Cellular Smaller in size Complex DNA Plants Cell Membrane Cell Wall Cell Membrane Cytoplasm Fluid portion of cell between the nucleus and cell membrane. Contains the other organelles. Chemical reactions occur in it. Like fruit in jello. 4

5 Nucleus Cytoskeleton Control center of the cell. Found throughout the cytoplasm. Support the cell Helps cell maintain it s shape Involved in cell movement. Network of protein filaments including microtubules and microfilaments. Controls most cell processes AND contains hereditary information of DNA DNA holds coded instructions for making proteins. Located near middle in animal cells but to the side in plant cells. Nucleolus Chromatin and Chromosomes Small, dense structures. Contains genetic information Chromatin becomes chromosomes when the cell divides The assembly of ribosomes begins here. 5

6 Nuclear Envelope Ribosomes Surrounds the nucleus. Has a double-membrane layer AND is dotted with nuclear pores that allow materials to move into and out of cell s nucleus. Endoplasmic Reticulum Rough Endoplasmic Reticulum 6

7 Smooth Endoplasmic Reticulum Golgi Apparatus (body) Contains enzymes that help produce lipids (phospholipids) Has no ribosomes. Located near the nuclear envelope. Breaks down drugs and alcohol. Stacked membrane sacs located near the end of the rough ER. Receives newly made proteins and lipids from the ER and distributes them to the plasma membrane and other organelles. Stores and secretes chemicals from the cell. Smooth ER Rough ER Vesicles Vacuoles Transfer proteins from the ER to the Golgi. Formed to transported material from place to place in the cell. Formed when part of the ER pinches off. Transport Vesicle Fluid-filled sacs surrounded by a membrane that functions in the temporary storage of materials. Store food, enzymes, water, or waste. Very large in plant cells 7

8 Mitochondria Energy Energy How much do you know? 1. Prokaryotes lack A. cytoplasm B. a cell membrane C. a nucleus D. genetic material 2. Who was the first person to identify and see cells? A. Anton Van Leeuwenhoek B. Robert Hooke C. Matthias Schleiden D. Rudolf Virchow 3. What is the job of the cytoskeleton? Structure and Support 4. Name the two organelles shown in the image. A. Smooth ER B B. Rough ER Energy 5. What organelle synthesizes proteins? Ribosomes Plant Cell Structures Cell Wall Lies outside the cell membrane. Composed of cellulose and gives shape, support, and protection of the cell. 8

9 Chloroplasts Animal Cell Structures Contain chlorophyll and carry out photosynthesis. In plants cells only Lysosomes Contain digestive enzymes. They digest excess or worn out cell parts, food particles, and invading viruses or bacteria. If lysosomes break, the chemicals may destroy the cell itself. Worn out cells are removed this way. Centrioles They exist in pairs outside the nucleus and are involved in cell division. They are composed of microtubules arranged in a circle. 9

10 Cilia are short, hair-like projections out of the plasma membrane. Used for locomotion in unicellular organisms. They are also found in multicellular organisms. Ex. protists and human windpipe Cilia and Flagella Flagella are whiplike projections that aid in movement. Ex. bacteria and sperm cells Cilia on a Protozoan. Flagella on a sperm cell. Similarities between plant cells and animal cells Eukaryotic Cell membrane Cytoplasm Multicellular Differences between plant cells and animal cells Differences between Plant Cells and Animal Cells Animal cells Plant cells Animal cells Plant cells Smaller in size Irregular shape No cell wall Larger in size Regular shape Cell wall present Vacuole small or absent Lysosomes Centrioles Present Large central vacuole Chloroplast 10

11 The Cell is like a Factory The Cell is like a Factory Cell Cell Wall Cell membane Cytoskeleton Nucleus Ribosomes Golgi Apparatus Mitochondria Factory Walls and the roof Security Officer Conveyor transport Main Office Assembly line Shipping office Power company 11