Guideline for Exam 1 – BSC1005 ONLINE – Dr. Ayala

Chapter 1:

Levels of biological organization (hierarchy)

Atom>Molecule>Cell>Tissue>Organ>Organ System>Organism>Population>Community>Ecosystem>Biosphere

Asexual vs. Sexual Reproduction

In asexual reproduction, genetic information comes from only one parent, and all offspring are virtually identical. One-celled organisms such as bacteria reproduce asexually by doubling and then dividing the contents of the cell. In asexual reproduction, genetic information comes from only one parent, and all offspring are virtually identical. One-celled organisms such as bacteria reproduce asexually by doubling and then dividing the contents of the cell.

Properties of living organisms

Organization>Energy Use>Maintenance of internal consistency>Reproduction, growth,development>Evolution

Taxonomy

o Kingdoms

Archaebacteria, Eubacteria, Protista, Fungi, Plantae, and Animalia

o Scientific name: Escherichia coli – Escherichia is genus while coli is species

domain:bacteria kingdom:eubacteriaphylum:proteobacteriaclass:gamma proteobacteriaorder:enterobacterialesfamily:enterobacteriaceaegenus:Escherichiaspecies:E. coli

Steps of scientific method domain:bacteria kingdom:eubacteria phylum:proteobacteria class:gamma proteobacteria order:enterobacteriales family:enterobacteriaceae genus:escherichia

species:E. coli Identify independent and dependent variables

Indepentent- What the investigater manipulates to determine whether it influences the phenomenon of interest

Dependent Variable – What the investigator measures to determine whether the independent variable influenced the phenomenom of interest.

Chapter 2:

Anatomy of atom: protons and neutrons (atomic nucleus); electrons in orbitals (2 electrons per orbitals).

The number of protons always equals the number of electrons in an atom, and that number is equal to the atomic number. The weight of an atom is determined by the number of neutrons and protons that are present in the nucleus. Atomic Mass = # Protons + # NeutronsThe atomic mass of carbon = 12The atomic # of carbon = 6 = the # of protons# neutrons = Atomic Mass - # protons# neutrons =12 - 6 = 6

Isotopes

An isotope is any of these different forms of a single element distinguished by the difference in the # of neutrons. For example, carbon has three isotopes, designated 12C (six neutrons), 13C (seven neutrons), and 14C (eight neutrons). The superscript in each isotope's symbol denotes the mass number.

Ions

An atom or group of atoms that has lost or gained electrons, giving it an electric charge

Chemical bonds:

o Covalent bond – type of chemical bond in which two atoms share electrons

polar vs. non polar- a covalent bond in which atoms share electrons equally. Polar – a covalent bond in which electrons are attracted more to one atom’s nucleus than to the other.

o Ionic bond- attraction between oppositely charged ions.

o Hydrogen bonds –weak chemical bond between opposite partial charges on two molecules or within one large molecule

Watero Hydrophobic (non-polar) – do not dissolve in water vs. hydrophilic (polar)-readily dissolve in water o Acids and Bases – pH scale-The pH scale ranges from 0 to 14, with 7 representing a neutral solution such as pure water (figure 2.16). An acidic solution has a pH lower than 7, whereas an alkaline, or basic, solution has a pH greater than 7. Note that it is a “reverse scale,” in that the higher the H+ concentration of a solution, the lower its pH. Thus, 0 represents a strongly acidic solution and 14 represents an extremely basic one (low H+ concentration).

o Buffers The pH scale ranges from 0 to 14, with 7 representing a neutral solution such as pure water (figure 2.16). An acidic solution has a pH lower than 7, whereas an alkaline, or basic, solution has a pH greater than 7. Note that it is a “reverse scale,” in that the higher the H+ concentration of a solution, the lower its pH. Thus, 0 represents a strongly acidic solution and 14 represents an extremely basic one (low H+ concentration).

4 types of macromolecules –Carbohydrates, Lipids, Proteins, Nucleic Acids. Dehydration (condensation) vs. hydrolysis chemical reactions - The pH scale

ranges from 0 to 14, with 7 representing a neutral solution such as pure water (figure 2.16). An acidic solution has a pH lower than 7, whereas an alkaline, or basic, solution has a pH greater than 7. Note that it is a “reverse scale,” in that the higher the H+ concentration of a solution, the lower its pH. Thus, 0 represents a strongly acidic solution and 14 represents an extremely basic one (low H+ concentration). Hydrolysis reactions break covalent bonds in polymers by adding water, while dehydration synthesis forms covalent bonds between monomers by rmoving water: thus the reactions are opposite.

Carbohydrates

o Sugars; know importance of 4 main polysaccharides (starch, glycogen, chitin, cellulose) Term: monosaccharide: Def: a sugar that is one five– or six–carbon unit, Term: monosaccharide:Def: a sugar that is one five– or six–carbon unit, Term: monosaccharide:Def: a sugar that is one five– or six–carbon unit

Proteinso Amino acids; peptide bond; structures - A protein is a chain of monomers called amino acids. Each amino acid has a central carbon atom bonded to four other atoms or groups of atoms (figure 2.22a). One is a hydrogen atom; another is a carboxyl group; a third is an amino group, a nitrogen atom single-bonded to two hydrogen atoms (—NH2); and the fourth is a side chain, or R group, which can be any of 20 chemical groups., The peptide bond,

which forms by dehydration synthesis, is the covalent bond that links each amino acid to its neighbor (figure 2.22b). Two linked amino acids form a dipeptide; three form a tripeptide. Chains with fewer than 100 amino acids are peptides, and finally, those with 100 or more amino acids are polypeptides. The four levels of protein structure are distinguished from one another by the degree of complexity in the polypeptide chain. The four levels of protein structure are distinguished from one another by the degree of complexity in the polypeptide chain. The four levels of protein structure are distinguished from one another by the degree of complexity in the polypeptide chain. The four levels of protein structure are distinguished from one another by the degree of complexity in the polypeptide chain. The four levels of protein structure are distinguished from one another by the degree of complexity in the polypeptide chain.

Lipids

o Hydrophobic; fats (triglycerides), phospholipids and sterols - Lipids are organic compounds with one property in common: they do not dissolve in water. They are hydrophobic because they contain large areas dominated by nonpolar carbon—carbon and carbon—hydrogen bonds, A triglyceride consists of three long hydrocarbon chains called fatty acids bonded to glycerol, a three-carbon molecule that forms the triglyceride's backbone. Although triglycerides do not consist of long strings of similar monomers, cells nevertheless use dehydration synthesis to produce them (figure 2.19). Each fatty acid has a carboxyl group, a carbon atom double-bonded to one oxygen and single-bonded to another oxygen carrying a hydrogen atom., Term: sterol:Def: lipid consisting of four interconnected carbon rings

Nucleic Acids

o Nucleotides (components) building block of a nucleic acid, consisting of a phosphate group, a nitrogenous base, and a five–carbon sugar

o DNA vs. RNA – function and structure- DNA contains A, C, G, and T, whereas RNA contains A, C, G, and U. DNA's main function is to store genetic information. One function of RNA is to enable cells to use the protein-encoding information in DNA. In addition, a modified RNA nucleotide, adenosine triphosphate (ATP), carries the energy that cells use in many biological functions. ATP,

Chapter 3:

Cells - prokaryotic vs. eukaryotic - prokaryote: Def: a cell that lacks a nucleus and other membrane–bounded organelles; bacteria and

archaea, eukaryote: Def: organism composed of one or more cells containing a nucleus and other membrane–bounded organelles

Cell theory – the ideas that all living matter consists of cells, cells are the structural and functional units of life, and all cells come from preexisting cells.

Contribution of scientists (Hooke, van Leuwenhoek, Schleiden/Schwann, Virchow) – Hooke discovered cells, van leu improved lenses to see vast more things, sc2 proposed the cell theory, German physiologist Rudolf Virchow added a third component to the cell theory in 1855, when he proposed that all cells come from preexisting cells.

Ribosomes – a structure built of RNA and protein where mRNA anchors during protein synthesis– found in ALL cell types

Cell membranes – structure and function - found in ALL cell types Prokaryotic cells (bacteria) a cell that lacks a nucleus and other membrane–

bounded organelles; bacteria and archaea

o Know structure and function of ALL bacterial parts - A rigid cell wall surrounds the cell membrane of most bacteria, protecting the cell and preventing it from bursting if it absorbs too much water. , Flagella (singular: flagellum) are tail-like appendages that enable these cells to move. One or more flagella are anchored in the cell wall and underlying cell membrane.

Eukaryotic cells (animals, plants, etc.) – also study cell diagrams - An astonishing diversity of other organisms, including humans, belong to domain Eukarya. Our fellow animals are eukaryotes, as are yeasts, mushrooms, and other fungi. Plants are also eukaryotes, and so are one-celled protists such as Amoeba and Paramecium. Despite their great differences in external appearance, all eukaryotic organisms share many features on a cellular level.

Know structure and function of ALL organelles and parts of animal and plant cells

Differences between plant cells and animal cells Plant cells have cell walls made of cellulose; animals cells have

a cell membrane, not a cell wall. The cell walls of plants contain plasmodesmata - microscopic

channels - that traverse the cell walls of the cells; animal cells contain no plasmodesmata

Plant cells have a big main vacuole in them; animal cells have many small vacuoles.

Plant cells contain chloroplasts and use photosynthesis to help produce food; no animal cell ever contains chloroplasts.

Plant cells are rectangular in shape; animal cells are circular, irregular or defined shapes depending on the type of cell

Animal cells have a centrosome; plant cells do not.

Animal cells have a cytoskeleton but plant cells do not.

Cilia vs. flagella- in eukaryotes, cilia and flagella are similar in their internal structure. Both structures move but they differ in their length and how they move. Cilia are short and move in wave like motions. Flagella are much longer and move with a whiplike motion.Cytoskeleton - The cytoskeleton is a structural framework with many functions. It is a transportation system, and it provides the structural support necessary to maintain the cell's characteristic three-dimensional shape (figure 3.22). It aids in cell division and helps connect cells to one another. The cytoskeleton also enables cells—or parts of a cell—to move.Cell communication - How do plant cells communicate with their neighbors through the wall? Plasmodesmata (singular: plasmodesma) are channels that connect adjacent cells. They are essentially “tunnels” in the cell wall, through which the cytoplasm, hormones, and some of the organelles of one plant cell can interact with those of another (see figure 3.25). Plasmodesmata are especially plentiful in parts of plants that conduct water or nutrients and in cells that secrete oils and nectars.

Plasmodesmata enable cell-to-cell communication and coordination of function within a plant. These tunnels, however, may also play a role in the spread of disease within a plant; viruses use them as conduits to pass from cell to cell.

o Plasmodesmata in plant cells vs. intracellular junctions in animal cells – plasmodesmata are tunnels that connect adjacent cell walls. These cells illustrate all three types of animal cell junctions. Tight junctions fuse neighboring cell membranes, anchoring junctions form “spot welds,” and gap junctions allow small molecules to move between adjacent cells.