Introduction to Biology What is a living organism?

How are living things different from nonliving things? Organization The ability to grow and develop The ability to respond to the environment The ability to reproduce

Organization An organism’s body is organized to fit its needs. Some bodies are simple because their function is simple; some are much more complex.

Growing/Developing Some organisms change from birth to their adult stage, while others stay about the same.

Responding to the Environment Organisms respond to the world around them.

Reproducing Living organisms have the ability to create new organisms similar to themselves; offspring.

Basic needs of living organisms Energy Comes from the sun Remember: producer vs. consumer Materials Carbon dioxide, nitrogen, oxygen, and water Living space Space to live and grow.

Unicellular vs. Multicellular Some organisms are made of only one cell: unicellular Others are made of many cells: multicellular The needs and properties of both types are the same.

Chapter 1: Introduction to Cells Lesson 1: Discovering Cells Cells and Heredity Chapter 1: Introduction to Cells Lesson 1: Discovering Cells

What are Cells? Cells form the parts of an organism and carry out many functions. In other words, they are the basic unit of structure and function in all living things.

Cells and Structure The structure of a living thing is determined by the different ways the cells are put together.

Cells and Function Living things must be able to live, grow, and reproduce to survive. In order to do this, they must have ways to get oxygen, food, and water and a way to get rid of waste. These processes are controlled by cells.

The Cell Theory Cell theory: widely accepted explanation of the relationship between cells and living things. All living things are made of cells. Cells are the basic unit of life. All cells are produced from other cells.

The Cell Theory History 1663: Robert Hooke observed cork and discovered the name for cells. 1674: Anton van Leeuwenhoek observed living cells in motion. 1838: Matthias Schleiden said all plants are made of cells. 1839: Theodor Schwann said all animals are made of cells. 1855: Rudolf Virchow said new cells only come from other cells.

Microscopes Microscope: an instrument that makes small objects look larger. Some use light and lenses, others use beams of electrons. A compound microscope uses two lenses to magnify an object; the total magnification can be found by multiplying the two lenses.

Microscopes Resolution: the degree to which two separate structure that are close together can be distinguished. Better resolution shows more details. Resolution improves with higher magnification.

Microscopes Electron microscopes use beams of electrons to magnify objects. Generally have higher magnification and better resolution than light microscopes, making them better for smaller objects.

Chapter 1: Introduction to Cells Lesson 2: Looking Inside Cells Cells and Heredity Chapter 1: Introduction to Cells Lesson 2: Looking Inside Cells

The Parts of a Cell Plant and animal cells have many of the same organelles, or parts that make up a cell. Each organelle has a unique structure and function that helps the cell survive.

Cell Membrane controls what goes in and out of the cell, like a screen. Allows food, water, etc. in and keeps harmful materials out. Found in both plants and animals.

Nucleus A cell’s control center, like a brain. Contains chromatin (DNA) to direct the cell’s function. Contains nucleolus, which is where ribosomes are made. Found in both plants and animals.

Ribosomes Small structures that make protein. Made in the nucleus, but travel throughout the cell. Found in both plants and animals.

Cytoplasm Clear, gel-like fluid that fills the region between the cell membrane and the nucleus. Moves constantly, carrying organelles around the cell. Found in both plants and animals.

Mitochondria Convert energy in food to energy that can be used to live. The “powerhouse” – “Mighty Mitochondria” Found in both plants and animals.

Endoplasmic Reticulum (ER) A maze-like structure. Some parts hold ribosomes (rough ER), while others do not (smooth ER). Found in both plants and animals.

Golgi Apparatus Receives proteins and other materials from the ER, packages them, and distributes them. Found in both plants and animals.

Vacuoles Stores food, water, and other materials, including waste. Found in both plants and some animals. Plants generally have one large, central vacuole.

Cell Wall An extra layer of protection outside of the cell membrane. Made of cellulose. Found in plants only.

Chloroplasts Green structures that make a plant green. Contains chlorophyll. Where photosynthesis occurs (captures sunlight and turns it into food). Found in plants only.

Lysosome Break down large food particles into smaller ones. Also recycle old cell parts. Found in animals only.

Animal and Plant Cells Plants ONLY Both Animals ONLY Cell wall Cell membrane Lysosome Chloroplasts Nucleus Sometimes vacuoles Central Vacuole Cytoplasm Mitochondria ER Ribosomes Golgi Apparatus

Unicellular vs. Multicellular In single-celled, one cell performs ALL functions. In multi-cellular, different cells perform different functions. They are specialized to do specific jobs.

Specialized Cells Multicellular organisms have different types of cells to perform different jobs. Red blood cells carry oxygen. Nerve cells transmit messages.

Levels of Organization Begins with the cell. Cells that perform the same job join together to form tissue. The tissues join together to make an organ, and organs that work together form an organ system.

Organ Systems lead to Organisms Different organ systems have specific purposes in an organism. Nervous: respond to environment Muscular: movement and heat Respiratory: inhale O2 and exhale CO2 Circulatory: delivers O2 in blood and remove CO2 in blood Digestive: breaks down food

Chapter 1: Introduction to Cells Lesson 3: Chemical Compounds in Cells Cells and Heredity Chapter 1: Introduction to Cells Lesson 3: Chemical Compounds in Cells

Elements and Compounds An element is a substance that cannot be broken down any further. Carbon, oxygen, etc. A compound forms when two or more elements combine chemically. CO2, H2O, etc.

Compounds in Cells Carbohydrates Provide the cell with energy Simple carbs are sugars and starches made from atoms of C, O, and H. Complex carbs, like starch and cellulose, are made in plants. Starch = chains of extra sugar Cellulose = makes cell wall

Compounds in Cells Lipids Fats, oils, and waxes; cannot mix with water Simple lipids are made of C, O, and H, and are used for energy and structure. Contains a molecule of glycerol bonded to C and H atoms (fatty acids).

Compounds in Cells Proteins Made of amino acids: long chains of elements (C, O, H, and N mainly). Structure and function depends on composition of amino acids. There are many types of proteins: Enzymes control chemical reactions Others support growth and repair matter

Compounds in Cells Nucleic Acids Hold instructions for maintenance, growth, and reproduction. Made of C, O, H, N, and phosphorous Broken into nucleotides Deoxyribonucleic acid (DNA) directs a cell’s function. Forms a double helix, like a ladder.

Compounds in Cells Helps with chemical reactions. Water Helps with chemical reactions. Helps cells keep their shape. Wilting plants don’t have enough water. Helps cells maintain a constant temperature.

Chapter 1: Introduction to Cells Lesson 4: The Cell in Its Environment Cells and Heredity Chapter 1: Introduction to Cells Lesson 4: The Cell in Its Environment

Transporting Materials Cell membrane controls what goes in and out because it is selectively permeable: some substance can cross the membrane while others cannot.

Passive Transport The movement of dissolved materials across a cell membrane without using energy.

Diffusion The process by which molecules spread out, moving from an area with many of them to an area with fewer of them. Helps cells maintain conditions necessary for life

Osmosis The diffusion of water through a membrane. If the concentration is higher outside of the cell, water moves in; if the concentration is higher inside of the cell, water moves out. You can easily see osmosis through plants.

Facilitated Diffusion Proteins form pathways for the sugars to pass through the membrane.

Active Transport The movement of materials across a membrane that uses cellular energy. Proteins are used to “pick up” materials and carry them across the membrane. Ca, K, and Na

Endo- and Exo- Endocytosis: cell membrane changes shape to engulf the particle. Large molecules enter the cell. Exocytosis: cell membrane forms an opening to the outside and forces the molecule out. Large molecules exit the cell.