Presentation on theme: "1 Cellular Structure SOL BIO 4.a-c. 2 Cell Theory The cell theory is the unifying theme in biology because it emphasizes the similarity of all living."— Presentation transcript:
1 Cellular Structure SOL BIO 4.a-c
2 Cell Theory The cell theory is the unifying theme in biology because it emphasizes the similarity of all living things. All organisms are composed of one or more cells. Cells are the smallest living units of all living organisms. Cells arise only by division of a previously existing cell.
3 Cell Characteristics Cells contain specialized structures to perform functions necessary for life. Cellular activities necessary for life include chemical reactions that facilitate: acquiring energy reproduction adaptation maintaining homeostasis
4 Cell Characteristics The basic processes necessary for living things to survive are the same for a single cell as they are for a more complex organism. A single-celled organism has to conduct all life processes by itself. A multi-cellular organism has groups of cells that specialize to perform specific functions.
5 Cell Characteristics All cells contain: Genetic material single circular molecule of DNA in prokaryotes double helix located in nucleus in eukaryotes Cytoplasm jelly-like substance that fills the cells interior Plasma membrane encloses the cell – phospholipid bilayer Phospholipids Membrane proteins
6 Cell Types Cell structure is one of the ways in which organisms differ from each other. 2 Types of Cells Prokaryote Eukaryote
7 Prokaryotic Cells Earth’s first cells were prokaryotes. The simplest life forms are the prokaryotes. Prokaryotic cells exist in two major forms: eubacteria and archaebacteria.
8 Prokaryotic Cells Prokaryotes are the Earth’s most abundant inhabitants. They can survive in a wide range of environments and obtain energy in a variety of ways.
9 Prokaryotic Cells Prokaryotes are cells that lack a nucleus and membrane bound organelles. Bacteria and related microorganisms are prokaryotes
10 Prokaryotic Cells Some use flagellum for locomotion ALL are UNICELLULAR Bacterial cell wall Flagellum Rotary motor Sheath
11 Generalized Prokaryotic Cell
12 Eukaryote Eukaryotes arose from prokaryotes and developed into larger more complex organisms. Eukaryotes are cells that contain a nucleus and organelles surrounded by a membrane, such as mitochondria and chloroplasts.
13 Eukaryote Can be both unicellular or multi-cellular Examples of eukaryotes are: All fungus, plant, and animal cells
14 Generalized Eukaryotic Cell
15 Cell Size Most cells are relatively small because as size increases, volume increases much more rapidly. longer diffusion time
16 Visualizing Cells
17 Nucleus Stores genetic material Contains DNA site where RNA is made Nucleolus: Chromatin and ribosomal subunits Nuclear envelope: Double membrane with pores Largest organelle BRAIN of the cell – controls protein synthesis
21 Ribosomes Ribosomes are RNA-protein complexes composed of two subunits that join and attach to messenger RNA. site of protein synthesis assembled in nucleolus
22 Ribosomes They can be found alone in the cytoplasm or attached to the endoplasmic reticulum. Alone in cytoplasm- makes proteins for use within the cell Attached to RER- makes proteins for export out of the cell
24 Endoplasmic reticulum transports materials through the cell Rough ER - studded with ribosomes Attached to nuclear membrane site of protein synthesis and processing Smooth ER - lacks ribosomes site of synthesis of phospholipids and the packaging of proteins into vesicles
25 Endoplasmic reticulum
26 Endoplasmic reticulum
27 Golgi apparatus collection of Golgi bodies Stacked flattened sacks Site where cell products are packaged for export Proteins are modified by being combined with fats or carbohydrates
28 Golgi apparatus Vesicles then pinch off from the Golgi body to be secreted (outside the cell) Involved in the production of lysosomes
31 Lysosomes vesicles produced by the Golgi apparatus. Lysosomes contain digestive enzymes and are involved in intracellular digestion of food particles, disease causing bacteria and worn out cell parts
34 Vacuoles Found in PLANT and ANMAL cells The vacuole acts a container, storing water and dissolved particles Plants have a large central vacuole for water storage Unicellular animals can use contractile vacuoles for movement
35 Organelles With DNA Mitochondria site of cell respiration Chloroplasts site of photosynthesis
36 Mitochondria "Powerhouse of the cell" - cellular metabolism Structure- outer and inner membranes, cristae Found in both plant and animal cells Very active cells have more mitochondria
37 Chloroplasts Chloroplasts are larger and more complex than mitochondria Contain green pigment called chlorophyll that absorbs sunlight in the first step of photosynthesis Found ONLY in PLANTS
38 Cell Membrane controls what enters and leaves the cell Found in ALL cells Phospholipid bilayer with transport proteins, and cholesterol (for flexibility)
40 Cell Wall provides support Found in PLANT and BACTERIA cells Made from cellulose
42 Cytoskeleton Long slender protein tubes and fibers that extend from the nucleus to the plasma membrane. The cytoskeleton contains three types of elements responsible for cell shape, movement within the cell, and movement of the cell: Actin filaments Microtubules Intermediate filaments
43 Cytoskeleton The cytoskeleton contains three types of elements : Actin filaments
44 Cytoskeleton The cytoskeleton contains three types of elements: Microtubules
45 Cytoskeleton The cytoskeleton contains three types of elements: Intermediate filaments
47 Centrioles Cylindrical structures found near the nucleus Made of hollow, tubular structures arranged in bundles Important in cell division Found ONLY in ANIMAL cells
49 Plant vs. Animal Cells PLANT CELL ANIMAL CELL Cell membrane Mitochondria Golgi apparatus Nucleus Cytoskeleton Ribosomes Endoplasmic reticulum Lysosomes HAVE: Cell Wall LARGE vacuoles Chloroplasts DO NOT HAVE: Centrioles HAVE: Centrioles DO NOT HAVE: Cell Wall LARGE vacuoles Chloroplasts
51 Plant Cell
55 Endosymbiosis Endosymbiosis theory suggests that eukaryotes arose from a symbiotic relationship between various prokaryotes. Heterotrophic bacteria became mitochondria. Cyanobacteria became chloroplasts. Host cell was a large eukaryotic cell.
62 Cell Differentiation Cell specialization occurs during the development of a multi-cellular organism. The genetic information necessary for all cellular functions remains in each cell but may not be used.