The Human Body The Cell

Chemistry of Living Things The stuff of life Elements: pure substance that cannot be broken down into any simpler substances by ordinary means Ex: foil wrap, bulb filament, diamond Compounds: two or more elements that are chemically joined together Ex: water (hydrogen and oxygen), table salt (sodium and chlorine)

Chemistry of Living Things Inorganic Compounds Compounds that may or may not contain the element carbon Most inorganic compounds do not contain carbon Ex: ammonia, rust, water Carbon dioxide is an exception

Chemistry of Living Things Organic Compounds A compound found in living things that contains carbon The carbon usually combines with other elements such as oxygen and hydrogen Organic refers to life

Chemistry of Living Things Organic compounds that are basic to life: Carbohydrates Fats and oils Proteins Enzymes Nucleic acids

Chemistry of Living Things Carbohydrates The main source of energy for living things Made of the elements carbon, hydrogen, and oxygen Ex: sugar, starch Many fruits are high in sugar; potatoes, rice, noodles, and bread are common sources of starch

Chemistry of Living Things Carbohydrates Carbohydrates are broken down inside the body into a simple sugar called glucose The body uses glucose to produce the energy needed for life activities If an organism has more sugar than it needs to meet its energy requirements, the excess is stored as starch for later use Starch = a stored form of energy

Chemistry of Living Things Fats and Oils Energy rich compounds made of carbon, hydrogen, and oxygen Lipids = scientific term for fats and oils Fats- solid at room temperature Oil- liquid at room temperature

Chemistry of Living Things Proteins Organic compounds made up of carbon, hydrogen, and oxygen, nitrogen, and sometimes sulfur and phosphorous Sources= eggs, meat, fish, beans, nuts, poultry

Chemistry of Living Things Proteins The building blocks of proteins are amino acids About 20 different amino acids that combine in many different ways to form thousands of different proteins Proteins perform many jobs Ex: growth and repair, build body parts such as hair and muscles, provide energy, carry oxygen throughout the body, and some make chemical substances that regulate body activities

Chemistry of Living Things Proteins – Enzymes Special type of protein that regulates chemical activities in the body Act as catalysts Speeds up or slows down chemical reactions Without enzymes, metabolism would not take place

Chemistry of Living Things Nucleic acids Organic chemicals Very large compounds Store information that helps the body make the proteins it needs Control the way amino acids are put together so the correct protein is formed “Blueprints” of life

Chemistry of Living Things Nucleic acids DNA – deoxyribonucleic acid Stores the information needed to build a protein Carries “messages” about an organism that are passed from parent to offspring RNA – ribonucleic acid “Reads” the message carried by the DNA Guides the protein-making process

Chemistry of Living Things Nucleic acids DNA RNA Together contain the information and carry out the steps that make each organism what it is

Chemistry of Living Things Review Most inorganic compounds do not contain the element carbon Organic compounds do contain carbon The organic compounds important to life are carbohydrates, fats and oils, proteins, enzymes, and nucleic acids

Chemistry of Living Things Review DNA and RNA are the nucleic acids that carry information that controls the building of proteins DNA also is considered the “blueprint” for life as it directs the development of an organism’s offspring

The Cell The Cell Theory 1665- Cells first observed by Robert Hooke Around the same time, Anton van Leeuwenhoek was observing materials such as blood, rainwater, and scrapings from his teeth He saw living cells in each material He called these things “animalcules” The smallest animalcules he observed were bacteria

The Cell Over the next 200 years… German botanist Matthias Schleiden discovered that all plant parts he examined were made of cells German zoologist Theodor Schwann made similar observations about animal parts German physicist Rudolph Virchow discovered that all living cells come only from other living cells

The Cell The Cell Theory Developed from the work of these and others All living things are made of cells Cells are the basic units of structure and function in living things Living cells come only from other living cells

Structures and Functions of Cells Most cells are much too small to be seen without the aid of a microscope One exception is the yolk of an egg, which is large single cell Within cells are even smaller structures called organelles

Structures and Functions of Cells Structures within a cell Function in providing protection and support, forming a barrier between the cell and its environment, building and repairing cell parts, transporting materials,storing and releasing energy, getting rid of waste materials, and increasing in number

Structures and Functions of Cells Most cells share similar characteristics Cell Membrane In a plant cell, just inside the cell wall In an animal cell, forms the outer covering of the cell Provides protection and support for the cell Animal cell membranes contain cholesterol which strengthen it Controls movement of materials into and out of the cell

Structures and Functions of Cells Most cells share similar characteristics Nucleus The control center of the cell Acts as the brain of the cell, regulating all of the activities of the cell Nuclear membrane Allows materials to pass into or out of the nucleus through pores

Structures and Functions of Cells Most cells share similar characteristics Chromosomes Rodlike objects in nucleus Control activities of the cell including growth and reproduction Responsible for passing on the traits of the cell to new cells Made up of large, complex compounds called nucleic acids

Structures and Functions of Cells Most cells share similar characteristics Nucleic acids The two nucleic acids found in cells are DNA and RNA Work together; store the information and carry out the steps in the protein-making process DNA remains in the nucleus RNA carries its protein-building instructions and leaves the nucleus

Structures and Functions of Cells Most cells share similar characteristics Nucleolus “little nucleus” Believed to be the site of ribosome production

Structures and Functions of Cells Most cells share similar characteristics Cytoplasm Clear, thick, jellylike substance found between the nucleus and the cell membrane Constantly moving, streaming throughout the cell

Structures and Functions of Cells Most cells share similar characteristics Endoplasmic reticulum Clear, tubular passageways Transportation system Carries proteins from one part of the cell to another

Structures and Functions of Cells Most cells share similar characteristics Ribosomes Grainlike bodies Produced in nucleolus Some attach to ER; some float freely in cytoplasm Primarily RNA Protein-making sites

Structures and Functions of Cells Most cells share similar characteristics Ribosomes The RNA in the ribosomes along with the RNA sent out from the nucleus directs the production of proteins Many ribosomes are found in the endoplasmic reticulum Once they have made the protein needed by the cell they can immediately drop them off into the passageways of the endoplasmic reticulum for transportation

Structures and Functions of Cells Most cells share similar characteristics Mitochondria Supply most of the energy for the cell The “powerhouse” of the cell Breaks down sugar into water and carbon dioxide gas, releasing large amounts of energy

Structures and Functions of Cells Most cells share similar characteristics Mitochondria The more active the cell, the more mitochondria it has Have small amount of their own DNA Once living organisms? Can self-replicate

Structures and Functions of Cells Most cells share similar characteristics Vacuole Storage tank Can store food, water, or other materials needed by the cell Can also store waste products Some animal cells have a few small ones Plant cells often have one large one In a plant, the water storage area

Structures and Functions of Cells Most cells share similar characteristics Lysosomes Common in animal cells Not often observed in plant cells Contain enzymes to break down large food molecules which then get passed on to the mitochondria Digest old cell parts “Garbage crew” of the cell

Structures and Functions of Cells Organelles found in plant cells only Chloroplasts Large, irregularly shaped green structures Contain green pigment chlorophyll Captures energy of sunlight to use in photosynthesis

Structures and Functions of Cells Organelles found in plant cells only Cell wall Strong and stiff Made of cellulose, a nonliving material Rigid cell wall helps to protect and support the plant Allows water, oxygen, carbon dioxide, and certain dissolved materials to pass into and out of the cell

Review Hooke, Leeuwenhoek, Schleiden, Schwann, and Virchow were scientists who contributed to the development of the cell theory Cell Theory All living things are made of cells Cells are the basic units of structure and function of all living things Living cells come only from other living cells

Review Cell wall-structure and support to plants Cell membrane-regulates what goes in/out Nucleus-control center Chromosomes-contain instructions for cell Endoplasmic reticulum-transportation Ribosomes-make protein Mitochondria-powerhouse of cell Vacuoles-storage tanks of cell Lysosomes-clean-up crew of cell Chloroplasts-capture energy of sun