What is Biology? What is Life? All this creates a Question: What is Life? Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. Cells – All living things are made of one or more cells. – A cell is the smallest unit capable of all life processes Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. – Living things maintain their internal environment. Homeostasis – All living organisms must maintain a stable internal environment in order to function properly. – The maintenance of a stable internal environment in spite of changes in the external environment is called homeostasis. Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. – Living things maintain their internal environment. – Living things pass on their traits. Heredity & Evolution – When an organism reproduces, it passes on its own traits to its offspring in a process called heredity. – Inherited characteristics change over generations. This process is called evolution Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. – Living things maintain their internal environment. – Living things pass on their traits. – Living things perform chemical activities. This is known as metabolism. Metabolism – Living organisms carry out different chemical reactions in order to obtain energy. – The sum of all the chemical reactions carried out in an organism is called metabolism. – Almost all of the energy used by living things originally comes from the sun. Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. – Living things maintain their internal environment. – Living things pass on their traits. – Living things perform chemical activities. This is known as metabolism. – Living things grow and develop. Growth and Development – All living organisms grow. – As organisms grow, many change. This process is called development. – Development differs from evolution because development refers to change in a single individual during that individual’s life. Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. – Living things maintain their internal environment. – Living things pass on their traits. – Living things perform chemical activities. This is known as metabolism. – Living things grow and develop. – Living things respond to a stimulus. Response to Stimuli – In addition to maintaining a stable internal environment, living organisms respond to their external environment. – Can you think of a way that you have responded to your environment today? Characteristics of Life • All life has seven characteristics in common: – Living things are made of cells. – Living things maintain their internal environment. – Living things pass on their traits. – Living things perform chemical activities. This is known as metabolism. – Living things grow and develop. – Living things respond to a stimulus. – Living things reproduce. Reproduction • Most living things can reproduce. Reproduction is the process by which organisms make more of their own kind from one generation to the next. The Cell Theory 1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells. Cells Timeline • Robert Hooke (1665): studied • • • • Go to Section: cork; saw tiny, regular shaped “boxes”; called them cells. Matthais Schleiden (1838) • All plants are made of cells Theodor Schwann (1839) • All animals are made of cells Rudolf Virchow (1855) Concluded all cells come from other cells •What is a VIRUS?? •Is it ALIVE???? Slide # 4 Viruses are 1/1000 to 1/10,000 the size of our cells. Slide # 5 What is a Virus? Classified as non-living: 1. are not made up of cells 2. Cannot live independently 3. can not reproduce on their own 4. Does not require food/does not grow, develop or move Slide # 7 Viruses consist of: 1.Nucleic acid: DNA or RNA (inner core) Capsid 2.Protein Coat, called a Capsid Cold virus Tobacco Mosaic Virus Flu virus Bacteriophage virus Notes: Cells http://www.studiodaily.com/main/technique/tprojects/6850.html The Cell Theory 1. All living things are composed of cells. 2. Cells are the basic units of structure and function in living things. 3. New cells are produced from existing cells. Cells Timeline • Robert Hooke (1665): • • • • Go to Section: studied cork; saw tiny, regular shaped “boxes”; called them cells. Matthais Schleiden (1838) • All plants are made of cells Theodor Schwann (1839) • All animals are made of cells Rudolf Virchow (1855) Concluded all cells come from other cells Cell Types There are two categories of cells: 1. Eukaryotic – Have a nucleus and membrane bound organelles Examples include plants, animals, fungi, and protists. Cell Types There are two categories of cells: 2. Prokaryotic – Have no nucleus and no membrane bound organelles Bacteria are an example. Make a Venn Diagram like shown below: Prokaryotic vs. Eukaryotic Cells Two specific organelles have made Eukaryotic cells be the most successful…. • Mitochondria – Consumes O2 to make energy (ATP) from sugar (food) • Chloroplast – Consumes H2O and CO2 as it takes in energy from the sun to make sugar (food) But guess what…. • These two organelles (mitochondria and chloroplast) are thought once be their own prokaryotic cell living inside a larger host cell…….these “prokaryotes” provided nutrients/oxygen to the host and in turn got a safe place to live. ENDOSYMBIOTIC THEORY Since BOTH these organelles have their OWN DNA even more support that they….. • Chloroplast have DNA • Mitochondria have DNA Endosymbiotic theory for dummies….. • https://www.youtube.com/watch?v=FQmAnmLZtE (mr. Anderson teacher talking with pictures) Two types of Eukaryotic cells are: • PLANT Cells • ANIMAL Cells Make a Venn Diagram like shown below: Organelles in Plant vs. Animal Cells Animal Cells: 1. Lysosomes 2. Vacuoles are much smaller Plant Cells: 1. Chloroplasts 2. Cell wall 3. Vacuoles are much larger Plant Cells Cell Wall Nucleus Chloroplast Characteristics of Plant Cells: 1. Rectangular or square shape 2. Cell wall that is composed mostly of cellulose Animal Cells Notice the circular shape of animal cells. Not all animals cells have this shape, but it is more common than not. Nucleus Cell membrane Organelles • Organelles - Specialized structures in a cell that have a specific function. Cell Membrane • Cell Membrane - Thin, flexible barrier around a cell; regulates what enters and leaves the cell (selectively permeable) Prokaryote Eukaryote Plant Animal Cell Wall • Cell Wall - Strong supporting layer around the cell membrane in plants, algae, and some bacteria that supports and shapes – Made of CELLULOSE in plants,chitin, etc. depending on the organism. Prokaryote Eukaryote Plant Nucleus • Nucleus – Contains DNA (genetic information) and instructions for the productions of proteins and other cellular processes – Bounded by the nuclear envelope Eukaryote Plant Animal Nuclear Envelope • Nuclear Envelope – Layer surrounding the nucleus of a cell covered in nuclear pores, which allow material to move into and out of nucleus Vacuoles • Vacuoles – Sac like structure that stores water, salts, proteins, and carbohydrates. – Plants contain large central vacuoles – Animals contain many smaller vacuoles Eukaryote Plant Animal Ribosomes • Ribosomes – small particles of rRNA; • Where proteins are assembled – Found throughout the cytoplasm and on the rough ER. Prokaryote Eukaryote Plant Animal Endoplasmic Reticulum • Endoplasmic Reticulum (ER) - Internal membrane system in cells in which lipid components of the cell membrane are assembled and some proteins are modified Rough Endoplasmic Reticulum • Rough ER- The portion of the ER involved in the synthesis of proteins – Given this name because of the ribosomes found on its surface. – Abundant in cells that produce large amounts of protein for export. Eukaryote Plant Animal • Smooth Endoplasmic Reticulum Smooth ER – Endoplasmic reticulum where ribosomes are not found on its surface – Involved in: 1. synthesis of lipids for cell membranes 1. detoxification of drugs (in liver cells) Eukaryote Plant Animal Golgi Apparatus • Golgi Apparatus - Modify, sort, and package proteins (from the ER) into vesicles for storage in the cell or secretion outside the cell. – Finishing touches are put on proteins before they are ready to leave the “factory.” Eukaryote Plant Animal Cytoskeleton • Cytoskeleton - Internal structure of some cells that gives shape and is involved in movement • Consists of 1. Microtubules- hollow and tube like; made of proteins called tubulins 2. Microfilaments- thin, thread like; made of protein called actin. Eukaryote Plant Animal Chloroplasts • Chloroplasts Organelles that capture the energy from sunlight and convert it into chemical energy in food (photosynthesis). – Like a solar power plant. – Contain the green pigment chlorophyll. Eukaryote Plant Mitochondria • Mitochondria - Organelles that convert the chemical energy stored in food (glucose) to make energy molecules for cells Eukaryote Plant Animal Lysosomes • Lysosomes – Vesicles from a Golgi that contain digestive enzymes that 1. Digest/break down lipids, carbohydrates, and proteins into small molecules that can be used by the cell 2. Break down/get rid of waste or worn out cell parts Eukaryote Animal Centrioles • Centrioles - Paired structures located in the cytoplasm of animal cells near the nucleus give rise to the spindle during cell division. Eukaryote Animal Cytoplasm Prokaryote Eukaryote Plant Animal • Cytoplasm – The fluid matrix that consists of water and dissolved substances such as proteins and nutrients. (cytosol) Cilia and Flagella • Cilia are short, numerous, and hair-like • Flagella are long, fewer, and tail-like • Both are for movement Prokaryote Eukaryote Animal Review: • A bacteria is a Prokaryotic or Eukaryotic cell? • A protist is a Prokaryotic or Eukaryotic cell? • A plant is a Prokaryotic or Eukaryotic cell? • DNA is found in both Prokaryotic and Eukaryotic cells. True or False Review: • A bacteria is a Prokaryotic or Eukaryotic cell? • A protist is a Prokaryotic or Eukaryotic cell? • A plant is a Prokaryotic or Eukaryotic cell? • DNA is found in both Prokaryotic and Eukaryotic cells. True or False Review: • A bacteria is a Prokaryotic or Eukaryotic cell? • A protist is a Prokaryotic or Eukaryotic cell? • A plant is a Prokaryotic or Eukaryotic cell? • DNA is found in both Prokaryotic and Eukaryotic cells. True or False Review: • A bacteria is a Prokaryotic or Eukaryotic cell? • A protist is a Prokaryotic or Eukaryotic cell? • A plant is a Prokaryotic or Eukaryotic cell? • DNA is found in both Prokaryotic and Eukaryotic cells. True or False Review: • DNA is found in both Prokaryotic and Eukaryotic cells. True or False • They both have DNA, except eukaryotes have it located in a membrane bound nucleus instead of thrown into the cytoplasm. What is the organelle labeled #9? What is the organelle labeled #9? MITOCHONDRIA What is the organelle labeled #5? What is the organelle labeled #5? ROUGH ENDOPLASMIC RETICULUM What is the organelle labeled #6? What is the organelle labeled #6? GOLGI APPARATUS VACUOLE What is the organelle labeled #14? What is the organelle labeled #14? CHLOROPLAS T What is the organelle labeled # 2? What is the organelle labeled # 2? VACUOLE