Sizes of Living Things - Christ University PDF

# Sizes of Living Things A scale bar is shown depicting sizes from 0.1 nanometers to 1 kilometer. - **Atoms** are the smallest things shown, followed by **amino acids** and **proteins**. - **Viruses** and **most bacteria** are visible under an **electron microscope**. - **Plant and animal cells**...

# Sizes of Living Things A scale bar is shown depicting sizes from 0.1 nanometers to 1 kilometer. - **Atoms** are the smallest things shown, followed by **amino acids** and **proteins**. - **Viruses** and **most bacteria** are visible under an **electron microscope**. - **Plant and animal cells**, **human egg**, **frog egg**, **ant** and **ostrich egg** are visible using a **light microscope**. - **Mouse**, **rose**, and **humans** are visible to the naked eye. - The **blue whale** is the largest organism pictured. ## What is the largest cell? ## What is the smallest cell? ## Are viruses cells? ## Who first cultured human cells successfully? # 1951 Johns Hopkins University: Dr. George Gey cultured first human cell line from HeLa cell (Henrietta Lacks) that are being grown in the laboratory all around the world. The image contains two black and white photos, one of a woman (Henrietta Lacks) and another of a man (Dr. George Gey). # The Immortal Life of Henrietta Lacks The image shows two covers of the book "The Immortal Life of Henrietta Lacks,” one from the original print and another from the HBO adaptation. There is a link to a movie trailer: [https://www.youtube.com/watch?v=FaFJya7FVSM](https://www.youtube.com/watch?v=FaFJya7FVSM) # Basic Properties of Cells - 6 Basic Properties of Cells: - Metabolism (anabolism/catabolism) - Reproduction (grow) - Locomotion (movement) - Differentiation - Communication - Evolve # Cell Size - **Prokaryotic cells** are 0.1–5.0 µm in diameter - **Eukaryotic cells** are 10–100 0 µm in diameter - **Size restricted by Surface/Volume (S/V) ratio** - Surface is membrane, across which cell acquires nutrients and expels wastes - Volume is living cytoplasm, which demands nutrients and produces wastes. - As cell grows, volume increases faster than surface - Cells specialized in absorption modified to greatly increase surface area per unit volume. # Surface to Volume Ratio A diagram of three cubes with 1, 2 and 4 layers, showing the surface area and volume of each. - Total Surface Area: - Cube with 1 layer: 96 cm² - Cube with 2 layers: 192 cm² - Cube with 4 layers: 384 cm² - Total Volume: - Cube with 1 layer: 64 cm³ - Cube with 2 layers: 64 cm³ - Cube with 4 layers: 64 cm³ - Surface Area PerCube/Volume PerCube (SurfaceArea/Volume) - Cube with 1 layer: 1.5/1 - Cube with 2 layers: 3/1 - Cube with 4 layers: 6/1 # What do you need to do to make life? - Lots and lots and lots of different kinds of amino-acid molecules. The image shows an arrow pointing to the different parts of an amino acid molecule: - NH2 - Amino-group - C - H (Hydrogen-atom) - COOH - Acid-group Amino-acid molecules come in 2 flavors: left-handed and right-handed. Life only uses left-handed molecules. You need the right type of proteins…millions of them in a single cell…to make it functional. # General structure of an aminoacid - The general structure of an amino acid: - R-C-COOH | NH2 | H - Amino Acid Structure: - H - | - H-N-C-C-OH | | Amino Carboxyl Group Group | R Side Chain # Peptide bond formation A diagram showing the peptide bond formation in a protein chain. - Starting point of a protein is called N terminal or amino terminal. - End point of a protein is the C terminal or Carboxy terminal. # Evolution: How did life begin (1) - Early earth’s atmosphere contains Hydrogen, Methane, Ammonia, Nitrogen gases. - Lightning provided energy to fuse the gases into different Amino-acid molecules. - Amino-acid molecules collide with one another to form protein molecules. - Protein molecules collide with one another to form a living cell. # Evolution: How did life begin (2) - At first, life was very simple and consists of “self-replicating molecules”. - Later, life learned to store genetic information in DNA molecules, with single cell organisms (bacteria) - And later, single cell organisms developed into simple multi-cell organisms (Example: coral polyp). # Evolution: How did life diversify? A timeline is shown that depicts life “changing” slowly over a long time: - Billions of Years - Present The image shows a variety of pictures of different types of organisms, including many that resemble marine organisms. - MORPHOLOGICAL DISTANCE - ORIGIN OF THE PHYLA - DARWINIAN PREDICTIONS # Evolution: How did life diversify? - When more and more living organisms are on earth, they compete for their food. - The stronger (faster, smarter, etc) animals will have a better chance to survive and reproduce. - This process of adaptation is called “natural selection”. # "Making amino-acid" according to Evolution - Put Hydrogen, Methane, Ammonia, Nitrogen together. - Use lightning (electric sparks) to fuse the gases into different Amino-acid molecules. - Any evidence that this can be done? # Making Amino-acids: Miller’s experiment - Miller put water, nitrogen, methane, ammonia, hydrogen and carbon dioxide in a flask. - The mixture was zapped for a week by high voltage sparks. - Miller was able to make a number of different types of amino-acid molecules. - Some scientists saw this as “proof” that life began on earth through evolution. An image of the Miller-Urey experiment apparatus is shown, including the following components: - Water Vapor - "Oceanic" Compartment - "Atmospheric" Compartment - Condenser - Spark Stimulates Lightning - Heat - Amino Acids # More problems with Miller’s experiment - Miller’s experiment cannot produce enough amino-acids (electrical sparks destroy the amino-acids!!!). - Miller’s (and later) experiment can only create proteins made with up to 30 amino-acids (some proteins have more than 1000 amino-acids!!!). - Proteins made in Miller’s experiment contain both left-handed and right-handed variants of amino-acids (living cells only use left-handed ones). # Asynchronous activity Find out the following: - Largest and smallest prokaryotic cells and their sizes - Largest and smallest eukaryotic cells and their sizes - Most abundant protein on Earth - Total cell no, cell size, genome size, no: of genes and no: of chromosomes of the following: - E coli - yeast - Drosophila - human beings (in a table format)