Presentation on theme: "Living Things How does the structure of a cell allow it to carry out the basic processes of life?"— Presentation transcript:
1 Living ThingsHow does the structure of a cell allow it to carry out the basic processes of life?
2 What is Life? Organisms are living things. Living things grow Living things are made up of cells
3 The Characteristics of Living Things Living things share an important characteristic.All living things have a cellular organization, contain similar chemicals, use energy, respond to their surroundings, grow and develop and reproduce.
4 The Characteristics of Living Things All living things have a cellular organization.All living things are made up of cells, the basic unit of structure and function in an organism.Organisms that are composed of one cell (singled-cell organisms) are unicellular.Ex: BacteriaOrganisms that are composed of many cells are multicellular.Ex: You (you are made up of trillions of cells, each cell specialized to perform a specific task.)
5 The Characteristics of Living Things All living things contain similar chemicals.Cells of living things are made up of chemicals.The most abundant chemical is water.Carbohydrates are the cell’s main energy source.Proteins and lipids are the building materials of cells.Nucleic Acid are the genetic material (the chemical instructions) that directs the cell’s activities.
6 The Characteristics of Living Things All living things use energy.The cell’s of organisms use energy to do what living things must do.An organism’s cell is always hard at work.
7 The Characteristics of Living Things All living things respond to their surroundings.A change in an organism’s surroundings that cause the organism to react is called its stimulus.Ex) Change in temperature, light, soundAn organism reacts to a stimulus with a response, an action or change in behavior.Ex) The sound of a horn startles you.
8 The Characteristics of Living Things All living things grow and develop.Growth is the process of becoming larger.Development is the process of change that occurs during an organism’s life to produce a more complex organism.
9 The Characteristics of Living Things All living things reproduce.To reproduce is the ability for an organism to produce an offspring that are similar to the parents.
10 Life Comes from LifeLiving things arise from living things through reproduction.Long ago, however, people believed in spontaneous generation, living things arise from nonliving things.Two famous scientists, Redi and Pasteur helped disprove spontaneous generation.
11 Life Comes from Life Redi Redi was able to prove that rotting meat does not produce flies.He had a controlled experiment (he carried out 2 tests that were identical in every aspect except for one factor).The one factor that a scientist changes is called the manipulated variable.
12 Life Comes from Life Pasteur Pasteur also disproved spontaneous generation.He demonstrated that new bacteria appeared in broth only when they were produced by existing bacteria.
13 The Needs of Living Things All living things must satisfy their basic needs for water, food, living space and stable internal conditions.
14 The Needs of Living Things All living things need water to survive.Organisms need water to obtain chemicals from their surroundings, break down food, grow, move substances within their bodies, and reproduce.
15 The Needs of Living Things All living things need food.All living things need a source of energy to live. This energy comes from food.Autotrophs- make their own food. They use the sun’s energy to make their own food.Ex) PlantsHeterotrophs- Do not make their own food; Obtain their energy by feeding on othersEx) People, mushrooms, etc.
16 The Needs of Living Things All organisms need a place to live.The surroundings of an organism MUST provide it with what it needs to survive.Some organisms must compete for a place to live, since there is limited amount of space on Earth.
17 The Needs of Living Things Organisms must be able to keep the conditions in their bodies stable, even when conditions in their surroundings change.The maintenance of stable internal conditions is called homeostasis.Ex) Your body temperature stays steady despite the changes in the air temperature.
18 An Overview of CellsCells are the basic unit of structure and function in all living things.Cells form the parts of an organism and carry out all of an organism’s processes, or functions.
19 An Overview of Cells Cells and Structure: The structure of an object means what that object is made up of, and how its parts are put together.The structure of living things are determined by the ways in which cells are put together.
20 An Overview of Cells Cells and Functions: An organism’s functions are the processes that enable it to stay alive and reproduce.Cells are involved in these functions.Some functions include: obtaining oxygen, absorb chemicals from food, etc
21 First Observation of Cells The invention of the microscope made it possible for people to discover and learn about cells.A microscope is an instrument that makes small objects look larger.Robert Hooke- one of the first people to observe cells.Anton van Leeuwenhoek- Built simple microscopes.
22 Development of Cell Theory The Cell Theory states the following:All Living things are composed of cells.Cells are the basic units of structure and function in living things.All cells are produced from other cells.
23 Looking Inside CellsThe tiny structures inside a cell, or organelles, carry out specific functions within the cell.Each organelle has a different function within the cell.
24 Enter the Cell Cell Wall To get into the cell, you must first pass through the cell wall.The cell wall is a rigid layer of nonliving material that surrounds the cells of plants and some other organisms.Animal cells do NOT have cell walls.A plant’s cell wall helps protect and support the cell.
25 Enter the Cell Cell Membrane: Located just inside the cell wall All cells have a cell membrane.The cell membrane controls what substances come into and out of a cell.Everything that the cell needs enters the cell through the cell membrane.The cell membrane helps prevent harmful materials from entering the cell.
26 Sail on into the Nucleus The nucleus of a cell, can be thought of as the cell’s control center, directing all the cell’s activities.The nucleus acts like the “brain” of the cell.Consists of the nuclear envelope, chromatin, and nucleolus.
27 Sail on into the Nucleus Nuclear Envelope:This is a membrane that surrounds the nucleus.It protects the nucleus.Materials pass in and out of the nucleus through the nuclear envelope.
28 Sail on into the Nucleus Nucleolus:Structure that floats byStructure where ribosomes are made.Ribosomes are the organelles where proteins are produced.
29 Sail on into the Nucleus Chromatin:These are the strands that float directly ahead of the nucleus.Contain genetic material, the instructions for directing the cell’s functions.Tells the nucleus how to direct the cell.
30 Organelles in the Cytoplasm The region between the cell membrane and the nucleus.Constantly moves.Many cell organelles are found in the cytoplasm.
31 Organelles in the Cytoplasm Mitochondria:Rod-shaped organellesknown as the “power houses” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions.Plural form- Mitochondrion
32 Organelles in the Cytoplasm Endoplasmic Reticulum:A maze of passage waysCarry proteins and other materials from one part of the cell to another
33 Organelles in the Cytoplasm Ribosomessmall, grain-like bodiesSome are attached to the endoplasmic reticulum, while others float in the cytoplasm.Function as factories to produce proteins.
34 Organelles in the Cytoplasm Golgi Bodies:A structure that looks like flattened sacs and tubes.Can be thought of as the cell’s mail roomIt receives the proteins and other newly formed materials from the endoplasmic reticulum, package them, and distribute them to other parts of the cell.Also, releases materials outside the cell
35 Organelles in the Cytoplasm ChloroplastOnly the cells of plants and some organisms have these organellesGreen in colorIt captures the energy from the sunlight and use it to produce food for the cell.Makes leaves green
36 Organelles in the Cytoplasm VacuolesA large water-filled sac floating in the cytoplasm.They are storage areas of cells.Most plants have one large vacuole.Vacuoles store food and other materials needed by the cell.Vacuoles also store waste products.
37 Organelles in the Cytoplasm LysosomesSmall, round structures containing chemicals that break down certain materials in the cell.They also break down old cell parts and release the substances so that they can be used again.The cell’s clean up crew.
38 Specialized CellsIn many-celled organisms, cells are often organized into tissues, organs, and organ systems.A tissue is a group of similar cells that work together to perform a specific function.An organ system is a group of organs that work together to perform a major function.An organ is made up of different kinds of tissues that function together.