Characteristics of LIVING THINGS. 1) Respond to its environment 2) Need Energy 3) Grows 4) Reproduces 5) Gets rid of Waste

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1 CELLS

2 Characteristics of LIVING THINGS 1) Respond to its environment 2) Need Energy 3) Grows 4) Reproduces 5) Gets rid of Waste

3 A Brief History of the Cell: 4min 21secs

4 Cell Theory: Modern Cell Theory: 1. The cell is the fundamental unit of structure and function in living things. 2. All living things are composed of cells. 3. Cells come from pre-existing cells.

5 Interesting Cell Facts: Your skin cells are all dead. Every inch of your surface is deceased. Run a finger along a dusty shelf and you are drawing a pattern very largely in old skin. Most living cells seldom live more than a month. Some notable exceptions are liver cells which last years and brain cells which last as long as you do. They simply renew their components in them (organelles). No part of you (at a cellular level) is older than 9 years.

6 Cell Diversity: Size The larger the cell, the more surface area it needs to exchange materials necessary for life. There are limits to how large a cell can grow. Continued cell growth can only occur if the cell divides.

7 Cell diversity: Shape Most cells are cubes or spheres. They may have many flat sides. Different shapes reflect different functions.

8 Cell Diversity: size: (Read only)

9 Cell Diversity: Organization Single-celled organisms are unicellular. They function independently. Multicellular organisms have more than one cell. They need other cells in order to function. Multicellular cells are more complex.

10 The Increasing Complexity of Multicellular Organisms: Cell ---> Tissue ---> Organ ---> Organ System ---> Organism 1. Tissues have similar cells. 2. Organs are composed of different tissues. 3. Organ systems are made of organs working together. Ex./ Heart cell, heart tissue, heart, circulatory system, human

11 Interesting Cell Facts: Your cells are a country of ten thousand trillion citizens, each devoted in some intensively specific way to your overall well-being. There isn t a thing they don t do for you. They let you feel pleasure and form thoughts. They enable you to stand and stretch and caper (skip). When you eat, they extract the nutrients, distribute the energy, and carry off the waste. They also remember to make you hungry, keep your hair growing, your ears waxed, your brain quietly purring. They manage every corner of your being. Billions of cells die for you daily and not once have you ever thanked one of them. Take a moment now to regard them with the wonder and appreciation they deserve. (READ ONLY)

12 Prokaryotic Cells: Cells that lack a membrane-bound nucleus are prokaryotes. Only bacteria have prokaryotic cell types. (OLDER & SIMPLE CELLS)

13 Prokaryotic Cells: 2min 24 secs

14 - Contain many small membrane-bound structures (organelles), which carry out specialized functions. Eukaryotic Cells: Examples: Animals, plants, fungi, protozoa, and algae all possess eukaryotic cell types.

15 Eukaryotic Cells: 3min 21 secs

16 Prokaryotic vs Eukaryotic:

17 Animal Cell: Animal cells are typical of the Eukaryotic cell: enclosed by a membrane. contains a membrane-bound nucleus and organelles. Unlike the eukaryotic cells of plants and fungi, animal cells do not have a cell wall.

18 Animal/ Plant cells: 4min 30 secs

Like other eukaryotes, the plant cell is: Plant Cell: enclosed by a plasma membrane allowing nutrients to enter and waste products to leave Unlike

19 Like other eukaryotes, the plant cell is: Plant Cell: enclosed by a plasma membrane allowing nutrients to enter and waste products to leave Unlike other eukaryotes: plant cells have retained a significant feature of their prokaryote ancestry, a rigid cell wall surrounding the plasma membrane.

20 Plant & Animal Cell Structures (Organelles) Read only as you have these definitions in your notebook already.

21 Nucleus: control centre of the cell; directs all cell activities. Chromosomes: found inside the nucleus. Contain DNA, which hold the construction plans for all parts of the cell. Cell Membrane: holds the contents of the cell in place, and acts like a gatekeeper controlling movements of materials such as nutrients and waste. Cytoplasm: a watery fluid that contains everything inside the cell membrane and outside the nucleus. Vacuole: is filled with fluid. Stores water and nutrients, such as sugar and minerals. Larger in plant cells than animal cells.

22 Cell Wall: protects and supports plant cell. Chloroplasts: food factories, contain chlorophyll that allows plants to make their own food. Chromosome: A chromosome is an organized structure of DNA. Mitochondria: circular or rod-shaped; power plant of cells. Nucleolus: is a non-membrane bound structure, found within the nucleus. Ribosomes: very, very small. Create proteins needed for cell growth, repair, and reproduction. Nuclear Membrane: encloses the genetic material (DNA) in eukaryotic cells. Endoplasmic Reticulum: carries materials through the cytoplasm. Golgi Apparatus: looks like flattened balloons; stores proteins and puts them into packages called vesicles. Lysosomes: patrol and clean the cytoplasm; the recyclers. They destroy harmful substances and invading bacteria.

23 Cells in their Environment

24 Cell Membranes Cells allow some material to enter and some to leave. Cells are permeable to some materials and impermeable to others. Permeable: permitting passage. Impermeable: not permitting passage. Small molecules pass easily. Medium-sized less easily. Large molecules cannot pass through without help from the cell. Certain molecules can pass through and certain molecules cannot, the membrane is said to be selectively permeable.

25 Organisms in Pond Water: 3min 32secs

blob of ink in a beaker of water Diffusion is one way that substances move

26 Diffusion: Diffusion: movement of molecules from high concentration to low concentration. eg. blob of ink in a beaker of water Diffusion is one way that substances move into and out of cells. Diffusion continues until the concentration of a substance is the same inside and outside the cell (EQUAL).

27 Osmosis Osmosis: Diffusion of water through a selectively permeable membrane. eg. plants without water look dead; plants with water are healthy.

Example 1: Water particles move in and out of

A B A B Example 2: Water particles move in and

(B). A B Example 3: Water particles leave the

28 Example 1: Water particles move in and out of the cell at the same rate (A), and the cell retains its normal shape. The plant cell is in its normal state (B). A B A B Example 2: Water particles move in and out of the cell by osmosis (A), causing the cell to swell. The plant cell swells beyond its normal size (B). A B Example 3: Water particles leave the cell by osmosis (A), causing the cell to shrink. The plant cell membrane shrinks away from the cell wall (B)

29 Cells in Solutions of Different Concentrations The movement of water into and out of cells is vital to all living things, and it is driven by imbalances in concentration.

TURGOR PRESSURE: When the concentration of water outside a plant cell is greater than the inside, water molecules enter through Osmosis. The water will fill the cell and cause it to swell.

30 TURGOR PRESSURE: When the concentration of water outside a plant cell is greater than the inside, water molecules enter through Osmosis. The water will fill the cell and cause it to swell. This outward pressure is called turgor pressure. When the cell is full, it will then resist turgor pressure. The lack of turgor pressure is what causes plants to stay rigid and not wilt.

31 The Wonders of the Cell: 4min 42secs

32 CHAPTER #1 REVIEW: THE CELL ASSIGNMENT IN BC SCIENCE 8 TEXTBOOK Complete Pg#50+51 #1-27

It helps scientists understand the workings of the human body and of other animals and plants

It helps scientists understand the workings of the human body and of other animals and plants Science 8 Unit 1 Worksheet Chapter 1 Cells Online resources: Click on Chapter 1 at the site below. http://www.nelson.com/bcscienceprobe8/student/weblinks.html Chapter 1.1 1. Organism is another word used