III.Living Organisms A.Properties of living organisms B.Cellular structure C.Metabolism and energy III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy

A.Properties of Living Organisms Hierarchical structural organization –Molecular organization Atoms, small molecules, polymers –Subcellular organization Organelles – Cells The simplest structure capable of having all of the properties of life –Multicellular organization Tissues, organs, organ systems –Ecosystem organization Populations, communities, biomes III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy

A.Properties of Living Organisms Growth and metabolism –The ability to assimilate nonliving matter and energy from the environment Response and adaptation to environmental conditions Reproduction Heredity Evolution III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy

B.Cellular Structure 1.Membranes 2.Types of cells 3.Eukaryotic cell structure III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 1. Membranes Membrane structure –A phospholipid bilayer with associated proteins III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

Phospholipids –Phospholipids are amphipathic, having both hydrophobic regions and hydrophilic “polar head groups” –Glycerol-based Phospholipids Glycerol molecule Two fatty acid chains Polar head group, attached via phosphate B. 1. Membranes III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 1. Membranes III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 1. Membranes –In aqueous suspension, amphipathic lipids will spontaneously arrange a bilayer structure, forming the boundary of a sphere that has water on both its inside and outside. Liposomes: models for studying bilayer structure. These are artificial bilayers, generally composed of pure phospholipid and water. III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 1. Membranes III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 1. Membranes Membrane proteins –Peripheral membrane proteins Are attached to either the inner or outer surface of a membrane –Integral membrane proteins Are embedded in the lipid bilayer of the membrane Usually pass completely through the membrane III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 1. Membranes Membrane Proteins (cont.) –Membrane proteins are especially notable in processes of transport, cell communication, and energy conversion –Different types of cell membranes have different protein compositions, depending on the membrane’s function. III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 2. Types of Cells Features common to all cell types –Bounded by a plasma membrane –Contain an aqueous suspension of proteins & other organic materials (the cytoplasm) –Utilize energy and raw materials through metabolism –Have both DNA and RNA –Reproduce by cell division processes III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 2.Types of Cells Eukaryotic cells –Have:complex internal membrane system compartmentalization membrane-enclosed organelles –DNA is enclosed in a membrane-bound nucleus –Includes: animal & plant cells, fungi, protozoa, algae –Diagrams: III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 2. Types of Cells Prokaryotic Cells –Have: No (or few) internal membranes –Many processes that are associated with organelles in eukaryotes (eg. respiration, photosynthesis) are mediated by specialized regions of the plasma membrane in prokaryotes III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 2. Types of Cells Prokaryotic Cells (cont.) –There is no membrane-bound nucleus in prokaryotes. Instead the DNA is located within a specialized region of the cytoplasm of the cell called the nucleoid region. There is no nuclear membrane surrounding the nucleoid. –Includes: The Bacteria The terms “prokaryotic cell” and “bacterial cell” often are used interchangeably –Diagrams: III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 3. Eukaryotic Cell Structures Nucleus –Location of the cell’s DNA –Major processes: DNA replication DNA expression (transcription) Ribosomes –Thousands are located suspended in the cytoplasm –Major process: Protein synthesis (translation) III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 3. Eukaryotic Cell Structures Cytomembrane system –Folded sacks of membranes within the cytoplasm –Carry out processing and export of the cell’s proteins –Two major components: Endoplasmic reticulum Golgi apparatus III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 3. Eukaryotic Cell Structures Mitochondria –Located in the cell’s cytoplasm –Major process: cellular respiration The mitochondria oxidize nutrient molecules with the help of oxygen Some of the energy is conserved in the form of chemical energy (energy-containing chemical compounds) that can be used for biological processes –Evolved from bacteria by a process called endosymbiosis III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

B. 3. Eukaryotic Cell Structures Chloroplasts – Located in the cytoplasm of plant cells, algae cells, and certain protozoan cells –Major process: photosynthesis Using the energy from light, CO 2 is converted into carbohydrates such as glucose –Evolved from bacteria by endosymbiosis III. Living Organisms A. Properties of Living Organisms B. Cellular Structure 1. Membranes 2. Types of Cells 3. Eukaryotic Cell Structures C. Metabolism and Energy

C. Metabolism and Energy 1.Basic concepts 2.Strategies for energy & raw materials 3.Respiration 4.Photosynthesis 5.The carbon cycle III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

Metabolism: the processes of catabolism and anabolism –Catabolism: the processes by which a living organism obtains its energy and raw materials from nutrients –Anabolism: the processes by which energy and raw materials are used to build macromolecules and cellular structures (biosynthesis) C.1.Basic Concepts III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

Cellular respiration –Nutrient molecules are oxidized to form CO 2 –Some of the energy released is stored as chemical potential energy (in ATP molecules) –ATP is used as a “fuel” by enzymes and cellular processes that require energy (for example, muscle contraction) C.1.Basic Concepts III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C.1.Basic Concepts Carbon fixation –Certain organisms can convert CO 2 into carbohydrates and other organic molecules –During this process, the carbon of the CO 2 becomes chemically reduced –This process requires the input of either chemical energy or light energy III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C.2. Strategies for Energy & Raw Materials Chemoheterotrophic organisms –Obtain their energy and raw materials from the catabolism of reduced organic nutrients (for example, Kellogg's Frosted Mini-Wheats) –Are not able to use CO 2 as a raw material for anabolism III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C.2. Strategies for Energy & Raw Materials Chemolithotrophic organisms –Obtain their energy from reduced inorganic compounds (for example, the hydrogen sulfide found in gasses from volcanic vents) –Use CO 2 as a raw material for anabolism –Use the chemical energy from the reduced inorganic compounds to convert CO 2 into carbohydrates III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C.2. Strategies for Energy & Raw Materials Photosynthetic organisms –Obtain their energy from light (for example, sunlight) –Use CO 2 as a raw material for anabolism –Use the light energy convert CO 2 into carbohydrates III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C. 3.Respiration Uptake of nutrients –Nutrient molecules are ingested or absorbed (for example, in the human digestive system) –The nutrients circulate and are transported into cytoplasm of the cells –Within the cells, the nutrient molecules are converted to glucose or similar simple substances III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C. 3.Respiration The catabolism of glucose –In the cytoplasm, glucose is partially oxidized to form pyruvic acid (the process of glycolysis) –Pyruvic acid is transported into the mitochondria and is converted into a form of acetic acid + CO 2 –In the mitochondria, the acetic acid is completely oxidized into CO 2 (the Krebs cycle) –The energy released during the Krebs cycle is captured by the mitochondrial membrane and used to synthesize ATP molecules. During this process, oxygen is used (and becomes water). III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C. 3.Respiration The regulation of glucose metabolism in animals –If the cell’s ATP level is high, it has enough energy and doesn’t need any more –Under these conditions, the cell has to store its excess glucose –A small amount of glucose can be stored in the form of glycogen –Most of the excess glucose is converted into acetic acid, then into fatty acids (which are stored as glycerides in adipose tissue) III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C. 4.Photosynthesis Occurs in the chloroplasts of algae and plants Light energy is absorbed by the pigments (mostly chlorophyll) in the chloroplast membranes The light energy is used to convert water molecules into oxygen (O 2 ). In the process, the light energy is converted to chemical energy. The harvested energy is used by enzymes in the chloroplast membranes to make ATP Some of the ATP is used to convert CO 2 into glucose molecules (carbon fixation) The plant can convert glucose into other important monomers (such as amino acids) III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle

C. 5. The Carbon Cycle Biogeochemical cycling –The concept that an element (such as carbon or nitrogen) is converted into different forms (“cycled”) by different organisms in an ecosystem –Cycling can also include non-biotic processes, such as volcanic activity (a natural process) or industrial processes (a result of human activity) –The carbon cycle: Cunningham, figure 2.19 III. Living Organisms A. Properties of Living Organisms B. Cellular Structure C. Metabolism and Energy 1. Basic Concepts 2. Strategies Respiration 4. Photosynthesis 5. The Carbon Cycle