CH 6 A Tour of the Cell 6

CH 6: A Tour of the Cell

6. 1 All organisms are made of cells

Intro Info: • Analogy: cells are to living things as atoms are to molecules • All organisms are unicellular or multicellular • B/C knowledge required microscopes…knowledge is fairly recent

3. Various types of Microscopes Light Microscope Electron Microscope (1950 s) (LM) (SEM)-surface (TEM)-internal Magnifies up to 1, 000 x 1000 x magnification For bacteria or larger Specimens must be killed • Micrographs= photographs taken through a microscope • Compound scopes= use two or more lenses

1. What evidence lead to the cell theory? • 1 st compound scopes used in 1600 s • Robert Hooke ( 1665) 1 st to describe “compartments” aka cells • Leeuwenhoek made additional detailed observations using precise lenses • All specimens observed were found to possess cells Cell History

2. Three main ideas of the Cell Theory • 1800 s evidence of observations led to cell theory – All living organisms are made of cells – Cells are the basic unit of structure and function (what makes up and operates the organism) – All cells come from other cells

4. Similarities and Difference between Plant & Animal Cells P vs. A

4. Similarities and Difference between Plant & Animal Cells Similarities Both types have Plasma Membrane Both types have Cytoplasm Both types have Nucleus Differences Only plant cells have chloroplasts Only plant cells have cell walls

5. Eukaryotic vs. Prokaryotic Cells Eukaryotic Prokaryotic E More complex, appeared later Have a nucleus and organelles Larger P Appeared on Earth 1 st No nucleus or membrane bound organelles Smaller Include animal cells, plant Include Bacteria cells, fungi cells, protist cells

6. 1 Vocabulary • • • Cell theory Micrograph Organelle Plasma membrane Nucleus • • Cytoplasm Cell wall Prokaryotic cell Eukaryotic cell

6. 2 Membranes organize a cell’s activities

1. Describe the structure of cellular membranes • Keep cell organized • Regulate transport of substances • Made of proteins and lipids (phospholipids-2 fatty acids) • Double layer, one hydrophobic, other hydrophilic • Allows boundaries between watery environments

2. Id the functions of the proteins found in the plasma membrane • Proteins bind to specific molecules and help them move across a plasma membrane

6. 2 Vocab • Phospholipid bilayer

6. 3 Membranes regulate the traffic of molecules

1. What is diffusion? • Overall movement of particles from high concentration (crowded) to low concentration (open space)

2. What role does a cellular membrane play in passive transport • Membranes allow certain particles to pass through (selectively permeable) – Dependent on size and electric charge • Nonpolar pass easily • Polar (ions) do not – Protein channels allow specific particles through

3. What is osmosis? • Diffusion of water

4. Hypertonic vs. hypotonic vs. isotonic solutions Hypertonic Hypotonic Isotonic High Low Equal concentration of solute and solvent Animals cell Animal cell will Cell will not will shrivel swell change

5. How is active transport different from passive transport? What is its function? Is… Active Transport Passive Transport Moving a solute against the concentration (from low to high)-requires energy Diffusion (from high to low) --does NOT require energy Allow movement of particles Function… To “accumulate” a particle

6. How do vesicles transport large molecules? • Exocytosis: vesicles will fuse with outer membrane and empty contents outside of cell

6. 3 Vocab • Diffusion • Equilibrium • Selectively permeable membrane • Passive transport • Facilitated diffusion • Osmosis • hypertonic • • • Hypotonic Isotonic Active transport Vesicle Exocytosis endocytosis

6. 4 Cells Build a Diversity of Products

1. In what ways does the cell nucleus direct the activities of the cell • Nucleus: – Contains DNA – Contains dark mass=nucleoulus (helps with ribosome productions) – Membrane has pores for in/out

2. List how the functions of the ribosomes, ER, and golgi apparatus are related Ribosomes ER: 2 types: Make or produce Produce and transport proteins Found on ER Golgi Apparatus Modify, store, or move proteins Smooth-no ribosomes on “processing or surface shipping center” *build lipid molecules (hormones) Rough-ribosomes on surface *common in cells that produce proteins

ER, Golgi, Ribosomes

3. Trace the path of a protein from the time it is produced by the ribosome on the ER until it reaches its destination. • Proteins ER ribosomes ER interior protein is captures into a vesicle moves to golgi processed and tranported to destination

3. What are the different functions of a vacuole and a lysosome? Vacuoles Lysosomes Membrane Pathways Membrane “sac” Membrane sac that Package, digests molecules move, and Store undigested Help nourish(feed) transfer molecules nutrients cells in/out Plants= 1 large protect against Animals=many bacteria, recycle damaged organelles small

Vacuoles vs. Lysosomes

4. How are undigested nutrients in a vacuole made available to a cell • Lysosome fuses with vacuole, releasing digestive enzymes which converts nutrients into substances cell can use.

6. 4 Vocab • • Nuclear envelope Nucleolus Ribosome Endoplasmic Reticulum • Golgi apparatus • Vacuole • lysosome

6. 5 Chloroplasts and Mitochondria energize the cells

1. How are the functions of the chloroplasts and mitochondria similar? Found: Chloroplasts In plants and algae Function: Trap light and convert it to energy (photosynthesis) Structure: Double membrane structure Mitochondria In all eukaryotic cells Performs cellular respiration: releases energy from sugars into ATP Double membrane structure

2. How does a cell use the energy produced by the mitochondria • In the chemical form of ATP

3. In what way is energy changed by reactions in a chloroplast? • Light energy is changed/converted to chemical energy (as organic molecules)

4. How is membrane structure important to the functions of mitochondria and chloroplasts. • Both have double membrane structure – Chemical reactions take place between inner and outer membranes – Folded membranes also increase surface area

6. 5 Vocab • Chloroplast • Mitochondria • ATP

6. 6 An internal skeleton supports the cell and enables its movement

1. What is the role of the cytoskeleton in cell movement Cytoskeleton: -Network of fibers that give cell internal support -made of two structures Microtubules Microfilaments give cell shape allow organelles to move within cell

2. How do microfilaments function in the cytoskeleton of a cell Microtubules Microfilaments give cell shape allow organelles to move within cell Picture

3. How do flagella differ in structure and function from cilia? Flagella Cilia • Both help with cell movement • Tail-like structures • Usually only 1 -2 • Move in S shape • Short hair-like • Usually lots of them • Row like oars

4. Give an example of coordination within a cell. • DNA instructs ribosomes to make proteins • Proteins are made and move through membrane pathways (ER and golgi) • Proteins are inserted into cell membrane to aid is transport

6. 6 Vocab • • Microtubule Microfilament Flagella cilia