Elements, Water, Cells, Membrane Transport, and Cell Division (Review #1) Flashcards
SPONCHNa CaFe
Sulfur
Phosphorus
Oxygen
Nitrogen
Carbon
Hydrogen
Sodium
Calcium
Iron
Sulfur
Amino acids (proteins – disulfide bridges)
Phosphorus
Phospholipids, Nucleic acids (DNA and RNA – phosphate in the backbone), ATP
Oxygen
Amino acids (proteins), Carbohydrates, Lipids, Nucleic acids (DNA and RNA), aerobic respiration (final electron acceptor at end of ETC)
Nitrogen
Amino acids (proteins – amine groups), Nucleic acids (DNA and RNA – nitrogenous bases), ATP
Carbon
forms foundation for all organic molecules/ compounds – can form up to 4 covalent bonds (compounds containing carbon and found in living organisms)
CHON
found in decreasing abundance from C to N in living organisms in this order)
Hydrogen
Amino acids (proteins), Carbohydrates, Lipids, Nucleic Acids, respiration (reducing agent – shuttles electrons), photosynthesis (reducing agent – shuttles electrons)
Sodium
Osmoregulation (nephron in kidney), action potentials (nerve signals – sodium channels open, sodium ions rush INTO nerve cell causing depolarization)
Calcium
Muscle contraction (released from sarcoplasmic reticulum to bind to troponin to expose myosin binding sites), Nerve cell transmission (calcium channels open at axon terminal, calcium ions rush INTO nerve cell causing vesicles with neurotransmitter to bind with pre-synaptic membrane and “dump” neurotransmitter into synaptic cleft)
Iron
Muscle contraction (released from sarcoplasmic reticulum to bind to troponin to expose myosin binding sites), Nerve cell transmission (calcium channels open at axon terminal, calcium ions rush INTO nerve cell causing vesicles with neurotransmitter to bind with pre-synaptic membrane and “dump” neurotransmitter into synaptic cleft)
Carbohydrates
(building blocks/ monomers are saccharides – sugars and starches)
Lipids
(building blocks are glycerol
and up to 3 fatty acids – fats/ oils)
Proteins
(building blocks are amino acids – enzymes, antibodies etc.)
Nucleic Acids
(building blocks are nucleotides – DNA, RNA, ATP)
Water is….
dipolar (has positive and negative charges, can form hydrogen bonds with other water molecules/ polar substances)
Thermal Properties of Water
-High specific heat : stabilizes environments for life (around them and within them) – a large amount of heat only raises water’s temp. a small amount – heat energy used to break hydrogen bonds BEFORE individual water molecules heat up
-High heat of vaporization: evaporative cooling for organisms (sweat, transpiration)
Cohesive and Adhesive Properties (due to hydrogen bonding)
-High surface tension: organisms live on surface/ maintains lung structure (pleural membranes)
-Transport in plants: Hydrogen bonds “stick” water molecules together (cohesion) and to other substances (adhesion - such as xylem walls) – allows movement (pull) of water through plants (transpiration)
Solvent Properties (due to polarity)
-Dissolves and transports polar/ hydrophilic substances - nutrients (organic compounds/ inorganic ions) etc. around/ through organisms
-Sap in plants (water up xylem and sugars down phloem)
Blood in animals (glucose, amino acids, fibrinogen, hydrogen carbonate ions etc.)
Note: hydrophobic substances (cholesterol, fats, oxygen) have special means of transport in living systems (lipoproteins in blood, haemoglobin etc.)
-Medium for metabolic reactions (Ex: glycolysis, DNA replication, transcription and translation, light-independent reactions, gas exchange/ clotting in blood plasma etc.)
Creation/ Breaking of Bonds: Water
-used in living systems to make and break chemical bonds
- water is removed from two subunits (H+ from one and OH- from another) of a macromolecule to create bonds, and water added to macromolecules (H+ and OH) to break bonds
Condensation
creating larger molecules by removing water (water is a product)
Hydrolysis
(hydro = water, lysis = “slice/ dice;” breaking): water is added to
break bonds/ break larger
molecules into smaller pieces
(ex: digestive processes)
Cell Theory Overview
-All living things made of cells
-Cells = smallest fundamental unit of life
-All cells arise from pre-existing cells
Evidence for Cell Theory
-Microscopes allow visualization of cells
-NOTHING smaller than a cell found to survive (on OWN) – if not made of cells
-Sterilization prevents cell growth (cells can only come from other cells) – Louis Pasteur
Exceptions to Cell Theory
Multinucleate muscle cells and fungal hyphae, giant algae, viruses, first cell origins (spontaneous)
Basic Functions of Life Carried Out by ALL cells
eproduction, growth, respiration (energy/ nutrients), cells, homeostasis, excretion, response, metabolism
Order of Organelles/ Cells/ Molecules in terms of SIZE
Cell membranes (smallest)
Viruses
Bacteria
Organelles
Eukaryotic Cells (largest)
Magnification=
measured/ actual
Surface Area
determines rate of exchange of materials (nutrients/ wastes)
Volume
influences metabolic reaction rate/ determines need of nutrients and amount of waste
As cell size increases….
SA:V ratio decreases (cells divide when too large to maintain high SA:V ratio)
What is a stem cell?
undifferentiated (pluripotent/ totipotent – can continuously divide and become any cell)
Therapeutic Use of Stem Cells
-Stem cells harvested from embryos – destroys/ kills embryo! (OR placenta/ umbilical cord)
-Exposed to biochemicals in lab to cause differentiation into desired cell type
-Transferred to patients who need them (skin cells for burn patients) – requires immunosuppression of patient first so do not reject/ monitoring for cancer following transfer
Differentiation
cells are able to carry out specialized functions by expressing some genes and not others
Prokaryotic Cells Overview
-Divide by binary fission (asexual reproduction)
-Have organelles WITHOUT membranes around them
-Mitochondria and Chloroplasts (Eukaryotic cells) thought to have originated from primitive prokaryotic cell that was engulfed (endocytosis) by a primitive predatory/ heterotrophic cell – Endosymbiotic Theory (Lynn Margulis)
Structures in Prokaryotic Cells and their functions
-Cytoplasm: Fluid containing enzymes for metabolic reactions
-Flagellum: Motility
-Ribosomes (70S): Protein synthesis
-Nucleoid: Region where DNA located(cellular control/ reproduction)
-Plasma membrane: Entry/ exit of substances
-Cell wall: Shape/ protection/ water uptake
-Capsule: Protection (from dehydration)
-Plasmid: Additional DNA (can replicate independently/ be exchanged – adaptation)
-Pili: Attachment (in some aid in exchange of genetic material)
Eukaryotic Cells Overview
-Have MEMBRANE-BOUND organelles (discrete structures that carry out specialized functions = allow compartmentalization/ increased efficiency)
-Note: all cells have a cell/ plasma
membrane, ribosomes (no membrane), cytoplasm, chromosomes/ DNA
Structures in Eukaryotic Cells and Their Functions
-Ribosomes (80S):
Protein synthesis (bound to ER = make proteins for excretion, or free floating = make proteins that stay/ used in cell)
-Endoplasmic reticulum*: (lots in glandular cells)
—–Rough – protein synthesis (excretion)
——Smooth – hormone production, detoxification, lipid production, transports substances to golgi etc.
-Nucleus: Contains DNA (cell control/ reproduction)
-Nucleolus: Makes ribosomes
-Lysosome: (animal cells) - only one membrane
“Slice and dice” – hydrolytic enzymes for intracellular digestion (Note: plant cells have plastids for this function)
-Golgi Apparatus (lots in glandular cells): Collects, stores, modifies, and “ships”/ transports cellular materials (often from RER)
-Mitochondria: Aerobic respiration (ATP)
-Centrosome/ Centrioles: Organize/ assemble microtubules (cell division/ motility/ cytoskeleton)
-Chloroplasts: Photosynthesis (in plants/ algae)
-Vacuoles: Storage of nutrients (starch, water, glycogen etc) – VERY large in plants
Similarities Between Prokaryotic and Eukaryotic Cells
-Both have DNA
-Both have a cell
membrane
-Both have
cytoplasm/ carry out all functions of life
-Both contain ribosomes
Prokaryotes vs. Eukaryotes: DNA Association
DNA is naked (no proteins) vs.
DNA associated with proteins (histones)