...Substance specific!!!!!!!!! Passive transport Osmosis LE 7-11a Molecules of dye Membrane (cross section) WATER Net diffusion Net diffusion Equilibrium Net diffusion Equilibrium Diffusion of one solute Net diffusion Net diffusion Net diffusion Equilibrium LE 7-12 Lower concentration of solute (sugar) Higher concentration of sugar H2O Selectively permeable membrane: sugar molecules cannot pass through pores, but water molecules can Osmosis Same concentration of sugar Lecture 5 Introduction to Domain Bacteria and Archaea (aka Kingdom Monera) The First Forms of Life 3.5-4.0 bya Simple ≠ primitive 4 Billion years of evolution!!! Prokaryotes are the Simplest Form of Life Small (1-5 μm) Uncomplicated structure Evolution and diversity chemical level Single cells colonies Prokaryotic Structural Diversity Limited to three shapes Spherical -> cocci Rod-shaped -> bacilli Helical -> spirochetes or spirilla Prokaryotes v. Eukaryotes See Table 27.2 All cells have: - Plasma membrane - Chromosomes - Cytosol - ribosomes Nuceoid No organelles Small High SA/V Nucleus Organelles Big Low SA/V Basic Prokaryotic Cell Structure Cytoplasm cell membrane cell wall DNA Basic Prokaryotic Cell Structure cell membrane cell wall Classification of the Prokaryotes Two main branches: Archaea...
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...1. • Identify the relationship between the conditions on early Earth and the origin of organic molecules: - Conditions of early Earth: _ Massive oceans existed _ Only small landmasses above the surface of the water _ No ozone layer _ Large amounts of radiation reached the Earth _ No free oxygen in the air _ Large amounts of volcanic activity; heat, ash, dust and gases into atmosphere _ Violent electric storms common _ Atmosphere contained some water vapour (H2O), hydrogen (H2), hydrogen cyanide (HCN), a lot of carbon dioxide (CO2), nitrogen (N2), possibly ammonia (NH3) and methane (CH4). - The chemicals of life are contained within the following basic organic compounds: water, carbohydrates, lipids, proteins, and nucleic acids. - These compounds are made up of hydrogen (H), oxygen (O), carbon (C), nitrogen (N) and some other common elements. - As you can see, the elements needed to create the basic organic compounds were already present in the atmosphere; i.e., H, O, C and N were already there. - The lack of an ozone layer, the frequent violent electric storms, and the volcanic activity of early Earth could have provided the energy for molecules to be formed. • Discuss the implications of the existence of organic molecules in the cosmos for the origin of life on Earth: - For life to have originated, the following events need to have happened: _ The required chemicals need to have been formed _ These chemicals need to have come together in a self-replicating...
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...membranes at the surface of cells and within cells (10 marks) Both the cell surface membrane and the membranes surrounding certain organelles have the same basic structure and similar functions. There are 5 major roles of membranes including separating cell contents from the outside environment; separating cell components from cytoplasm; cell recognition and signalling; holding the components of some metabolic pathways in place and regulating the transport of materials into or out of cells. The phospholipid bilayer is the basic structural component of all biological membranes. A bilayer is formed when phospholipid molecules are completely surrounded by water. The hydrophilic (water-loving) heads stick in the water, while the hydrophobic (water-hating) fatty acid tails point towards each other in a mirror image. The formation of the tails creates a barrier to many molecules, separates the cell contents from the outside world and gives stability. Mechanical stability is supported by cholesterol in the bilayer. This steroid molecule fits between fatty acid tails and helps make the barrier more complete, so substances like water molecules and ions cannot pass easily and directly through the membrane. The structure of the membrane is called the fluid mosaic model because the membrane is fluid (the phospholipid molecules are not actually bonded) and because of the mosaic arrangement of the protein molecules. Inside the fluid mosaic model are various protein molecules floating in the phospholipid...
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...inside any cell is being done by enzymes. If you understand enzymes, you understand cells. A bacterium like E. coli has about 1,000 different types of enzymes floating around in the cytoplasm at any given time. Enzymes have extremely interesting properties that make them little chemical-reaction machines. The purpose of an enzyme in a cell is to allow the cell to carry out chemical reactions very quickly. These reactions allow the cell to build things or take things apart as needed. This is how a cell grows and reproduces. At the most basic level, a cell is really a little bag full of chemical reactions that are made possible by enzymes! Enzymes are made from amino acids, and they are proteins. When an enzyme is formed, it is made by stringing together between 100 and 1,000 amino acids in a very specific and unique order. The chain of amino acids then folds into a unique shape. That shape allows the enzyme to carry out specific chemical reactions -- an enzyme acts as a very efficient catalyst for a specific chemical reaction. The enzyme speeds that reaction up tremendously. For example, the sugar maltose is made from two glucose molecules bonded together. The enzyme maltase is shaped in such a way that it can break the bond and free the two glucose pieces. The only thing maltase can do is break maltose molecules, but it can do that very rapidly and efficiently. Other types of enzymes can put atoms and molecules together. Breaking molecules apart and putting molecules together...
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...is that cells are the basic unit of life. Everything is made up of cells. Cells are the building block all living things. They provide structure and determines what goes in and out. Another common concept is that evolution is the force behind new species. Evolution is modification in the genetic characteristics of biological populations over consecutive generations. Evolutionary processes...
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...Area of the cell | Function of the cell | Cell-Cells are the basic building blocks of all living things. They provide structure for the body, and also take in nutrients from food and convert those nutrients into energy and carry out specialized functions. | In the human cell, firstly we have the red blood cells; these carry oxygen around the body from our lungs, to the rest of our body. The nerve cells carry nerve impulses to different parts of the body which carry electrical signals around the body. The female reproductive system function (in the cell) is to join with the male cell and providing food for the new cell’s that has been formed. | Organelle-Organelles are tiny structures that perform very specific functions within the calls. The term is a reference to organs, and the way these structures operate in cells, to the way organs function in the body. Each has its own task, such as producing energy. | Organisms are composed of cells, and these cells have specific structures within in them and this allows them to carry out their functions. The fine detail of the cell (which could be revealed by an electron microscope) this is called the cell’s ultrastructure. Organelles perform different functions within a cell, and this is called the division of labour. | Nucleus- The nucleus is the central and most important part of an object, movement, or group forming the basis for its activity and growth. It help’s controls eating, movement and reproduction. The nucleus is a...
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...CELL BIOLOGY AND GENETICS ASSIGNMENT TOPIC: CELL MEMBRANE [pic] INTRODUCTION Cell membranes are crucial to the life of the cell. It encloses the cell defines its boundaries, and maintains the essential difference between the cytosol and the extra cellular environment. Inside the cell the membranes of the endoplasmic reticulum, Golgi apparatus, mitochondria, and other membrane bound organelles in a eukaryotic cell maintain the characteristic differences between the contents of each organelle and the cytosol. Ion gradients across membranes, established by the activities of specialized membrane proteins, can be used to synthesize ATP to drive the transmembrane movement of selected solutes, or in nerve and muscle cells, to produce and transmit electrical signals. In all cells the plasma membrane also contains proteins that act as sensors of external signals allowing the cell to change its behavior in response to environmental cues; these protein sensors, or receptors, transfer information rather than ions or molecules across the membrane. [pic] THE STRUCTURE OF THE CELL MEMBRANE All biological membranes have a common general structure: each is a very thin film of lipid and protein molecules, held together mainly by non covalent interactions. Cell membranes are dynamic, fluid structures, and most of their molecules are able to move about in the...
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...Without this part of an experiment, a scientist would have no way of knowing if the treatment worked or not: Control group The control group is not subjected to the experimental treatment, thus, if there is a significant change in the test group but not the control group, then the treatment worked. Hypothesis Conclusion Observation Testing Question 3 1 / 1 pts Which of the following is not considered a basic theory of biology? Gene Ecosystem Cell Homeostasis The notch is an adaptation for feeding on shrubs. an experimental variable. a species. Question 7 1 / 1 pts Which of the following levels of taxonomy is the least inclusive? Class Order Family Genus The levels of taxonomy are, from most to least inclusive: domain, kingdom, phylum, class, order, family, genus, and species. Phylum Question 8 1 / 1 pts A possible explanation for a natural event is known as Atomic Atomic theory is a basic theory of chemistry and physics, not biology. Question 4 1 / 1 pts While examining a drop of pond water under the...
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...Bio 101 Review Sheet Test #1 (Chapters 1-3) Chapter 1 1. Cell is basic unit of life 2. Hierarchy of life figure 3. 3 Energy categories and examples of each Producer-plants and some microbes Consumer-humans and other animals Decomposer-fungi and other animals 4. Energy transfers are not 100% efficient – why? Cant capture all of the energy supplied by one source a. Where does all energy for biology come from? sun 5. Homeostasis- state of internal consistency or equilibrium 6. 2 types of reproduction asexual and sexual b. Benefits to sexual reproduction benefit of tremendous variation 7. Adaptation inherited characteristics or behaviors that enables an organism to survive and reproduce successfully in a given environment c. How it contributes to natural selection and evolution individuals with the better combinations of genes survive and reproduce 8. Evolution change in genetic makeup of a population 9. Why it’s important to take all your antibiotics so all of the bacteria can be eliminated, some of the bacteria can become stronger. 10. Taxonomy classification of life’s diversity 11. What our species name is homo sapiens 12. Order of taxonomic categories – mnemonic device! Domain, kingdom, phylum, class, order, family, genus, species 13. 3 domains bacteria, archaea, eukaryote d. Basic differences e. What our domain is f. What domain universal ancestor likely is in archaea ...
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...diagrams provided. The majority of the material in these beginning chapters should be a review for you. If need be, focus on those areas which may seem less familiar. After reviewing this material independently during the summer, it is expected that you have a solid understanding of these basic concepts for the start of this course. Prepare any specific questions that you may have. Again, this is an independent review and you will be expected to know these concepts for future use and assessment. This introductory material will not be covered in detail during class time. Chapter 1: Introduction: Themes in the Study of Life 1. Explain the importance of a biological hierarchy in terms of biological organization. 2. Why must scientists study the interactions of organisms with each other and the environment? 3. Comment on the relationship between structure and function in biology. 4. How specifically is the cell life’s basic unit of structure and function? 5. What is the significance of DNA to organisms? 6. Explain the basic concept of a biological feedback system. How does it work? 7. Explain briefly how life’s vast organisms are classified. Give the basic ideas. Make sure to include domains in your discussion. 8. Explain Darwin’s mechanism of evolutionary adaptation called natural selection. 9. Explain why “editing” is an appropriate metaphor for how natural selection acts on a population’s heritable variations. ...
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...Organic compounds also contains other elements such as hydrogen, oxygen, phosphorus, nitrogen, or sulfur. The foods you eat provide the organic compounds that your cells are made up of and that they use to function. Organic compounds give the elements carbon, hydrogen, oxygen (“CHO”) that are needed to make biological macromolecules. Biological macromolecules, are large molecules (also known as polymers). A monomer is a molecule that is able to bond in long chains. Monomers are small molecules that may be joined together in a repeating fashion to form more complex molecules called polymers. Usually, polymers are organic (but not necessarily). Hydrogen bonds are responsible for the properties of water and many biological molecules. Macromolecules, that are necessary for life, include carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates...
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...eukaryotic cell. ANSWER: Prokaryotic and Eukaryotic organisms: are composed of cells, the basic unit of life, with each cell surrounded by a cell membrane while membranes are composed of phospholipids, proteins and carbohydrates arranged in a fluid mosaic structure. The main different between the both cell organism is nucleus: Prokaryotic cells are smaller and simpler organisms without no nucleus but most are unicellular, while eukaryotic cells are larger organisms with a nucleus but often multicellular. Differences Prokaryotic cells Eukaryotic cells Protein DNA is circular, without protein. DNA is associated with protein to form chromatin. Cell wall Cell division is by binary fusion Usually...
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...a polar molecule The shape of a water molecule and its polarity make hydrogen bonding possible, A hydrogen bond is a weak attraction between a slightly positive hydrogen atom and a slightly negative atom. (They are partial charging) * Can occur between atoms of different molecule or within the same molecule * A single hydrogen bond is easily broken while multiple hydrogen bonds are collectively quite strong. * Help to maintain the proper structure and function of complex molecules such as proteins and DNA. Oxygen attracts the shared electric and is partially negative Hydrogens are partially positive. Properties of water * Water molecules cling together because of hydrogen bonding * This association gives water many of its unique chemical properties * Water has a high heat capacity * The presence of many hydrogen bonds allow water to absorb a large amount of thermal heat without a great change in temperature * The temperature of water rises and falls slowly * Allows organisms to maintain internal temperatures. * Water has a high heat of vaporization * Hydrogen bonds must be broken to evaporate water. * Bodies of organism cool when their heat is used to evaporate water. * Water is a good Solvent * Water is good solvent because of its polarity * Polar substances dissolve readily in water * Hydrophilic molecules dissolve in water (sugar) * Hydrophobic molecules do not...
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...Cells Biology- the study of life and living organisms Living- uses energy, maintains itself, capability to reproduce, and development/growth; also part of a population that evolve (each generation differs from the ones before and after) Cells- basic unit of life Prokaryotic- lacking nucleus Bacteria “archaea” Eukaryotic- nucleus Plants Animals Fungi Eukaryotic Nucleus- surrounded by a double membrane; contains DNA Linear chromosomes Cytoplasm contains everything outside of the nucleus Cytoskeleton crisscrosses the cell- holds shape and allows for cell movement Cytoplasm contains organelles- each plays a role in the functioning of the cell Organelles are surrounded by membranes Ribosomes- assemble proteins, only organelle not surrounded by membrane; some are suspended in cytoplasm and some are attached to Rough Endoplasmic Reticulum Rough Endoplasmic Reticulum- assembles proteins for the cell membrane or outside of the cell Smooth Endoplasmic Reticulum- assembles membranes Golgi Apparatus- “post office of the cell” Lysosomes- “garbage disposal of the cell” eats organic waste/ damaged organelles; some used to destroy bacteria Vacuoles- sacs surrounded by membrane used to store/expel nutrients or other materials such as pigments and hormones. Mitochondria- organelles that break down molecules to obtain energy for the cell Chloroplasts- plant cell structure that captures energy from sunlight to build molecules Cell membrane- defines...
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...Homework 1 Question 2. Phagocytosis is when larger solid particles are taken into the cell by being surrounded by the plasma membrane and passing through. Endocytosis is when smaller more soluble particles are taken in by the plasma membrane forming a sort of hole and then the hole is pinched off containing the smaller particles turning into a vesicle which is taken where it needs to go. Question 5. A scientist might choose light-microscopy over electron microscopy because you can use living cells and watch how different factors affect them. Electron microscopy might be used because it has better resolution so you can see more details and depth to determine what the sample really looks like. Question 7. Basic light microscopes require chemical staining because most of the cells are not visible under normal light conditions. The cell material doesn’t absorb visible light so they look invisible. Another way of visualizing samples is by using fluorescence. Most of the chemical stains bind to the whole molecule or group of molecules instead of a specific part or specific molecule. You can go around this problem by using fluorescent microscopy. The fluorescent marker can be attached to a specific place or molecule so that you only see the part that you want too because if you are using a fluorescent microscope you will only see the part or molecule that fluoresces. Confocal scanning and deconvolution microscopy make fluorescent microscopy better by allowing you to focus...
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