Plants and Humans Exam 1 Study Guide
1) Characteristics of Living Organisms
- composed of cells
- respond to stimuli
- growth and development
- ability to evolve
2) Hierarchy of smallest to largest entity (atom to biosphere) and definitions
- atom: smallest “functional” unit of all chemical substances (molecules). Cannot be broken down
- molecule: two or more atoms connected by chemical bonds - organelle: membrane-bound sub-cellular structure with its own unique function
- cell: the simplest unit of an organism
- tissue: the association of many cells of the same type
- organ: two or more types of tissue combined to perform a common function
- organism: a living thing that maintains an internal order and is separate from the environment
- species: group of related organisms sharing a distinct form - population: group of individuals of the same species that occupy the same environment
- community: assemblage of populations of different species living in the same plate/time
- ecosystem: biotic community of populations and the abiotic environment affecting that community
- biosphere: all regions on the Earth and in the atmosphere where organisms exist
3) The scientific method:
- hypothesis: a proposed explanation for a natural phenomenon. It is based on observations or experimental studies. *any hypothesis must be accompanied by a “null hypothesis”, which is a hypothesis of “no difference” or “no change”. A hypothesis must make predictions that can be supported or rejected. If you want to learn more check out What does homology mean?
- theory: a broad explanation of some aspect of the natural world. It is substantiated by a large body of evidence. It allows us to make many predictions. It can never be proved to be true (“Due to overwhelming evidence, it is extremely likely to be true”). The two key attributes of a theory are consistency with a vas amount of known date and the ability to make many correct predictions We also discuss several other topics like What is the meaning of rock in geology?
- Scientific method order of operations:
1. Observation: specific, observation based question you are trying to
2. Hypothesis: plausible explanation for observation
3. Prediction: outcome you believe will come from experimentation 4. Experiment: gathering of data appropriate to address question 5. Results: organized and detailed mathematical data We also discuss several other topics like Who is francis sumner?
6. Conclusion: accept or reject hypothesis. Null hypothesis not rejected = reject hypothesis. Null hypothesis rejected = accept hypothesis.
4) Energy: the ability to promote change or do work; comes in many forms (light, thermal, atomic, electrical, mechanical, chemical) - kinetic energy: energy associated with movement (football player running) Don't forget about the age old question of What is the meaning of genomics in biology?
We also discuss several other topics like What is the function of neurons?
- potential energy: energy due to structure or location of substance (arrow being pulled back in a bow)
- chemical energy: potential energy held in molecular bonds - 1st law of thermodynamics: “law of conservation of energy”. Energy cannot be created or destroyed. Can be transformed from one type to another (ex. Chemical energy into heat energy) If you want to learn more check out What is the meaning of extracellular matrix?
- 2nd law of thermodynamics: transfer or transformation of energy from one form to another increases entropy. Entropy is the degree of disorder of a system (energy that cannot be harnessed to do work; any transfer of energy ALWAYS results in a loss of energy as heat; no energy transfer is 100% efficient)
5) Metabolism: all chemical reactions within a cell that allows an organism to maintain structures and grow and most importantly, respond to the environment
Catabolism: the breakdown of larger molecules into subunits releasing chemical bond energy
Anabolism: chemical reactions responsible for building larger Oxidation: removal of electrons
Reduction: addition of electrons
6) ATP (Adenosine Triphosphate): primary energy carrying molecule in the cell; bond between the 2 terminal PO4 are high energy bonds; if terminal PO4 is removed, energy is released and can be ‘captured’ by the cell to do work. Many proteins use ATP as a source of energy
7) Carbohydrates: composed of carbon, hydrogen, and oxygen atoms. Most of the carbon atoms in a carbohydrate are linked to a hydrogen atom and a hydroxyl group (ex.
Proteins: polymers are composed of amino acid monomers. Types = structural, transport, and enzymes
Lipids: fats and fat-like substances (composed predominantly of hydrogen and carbon atoms. Characterized by their water repellent properties and inability to dissolve in water (hydrophobic). Three main lipids in plants = triglycerides (3 fatty acids, both saturated and unsaturated, giving them all very different qualities), phospholipids (glycerol bound to 2 fatty acids…amphipathic molecule with a polar
head and a nonpolar tail), waxes (harder and more water resistant than fats, comprise outermost layer of leaves, stems, etc)
Nucleic acids: large molecules made up of nucleotide subunits; responsible for storage, expression, and transmission of genetic information. Two types = DNA (store genetic information) and RNA (decodes this information into instructions for a polypeptide chain). Both comprised of subunits called nucleotides (Purines: adenine, guanine. Pyrimidines: Cytosine, Thymine, and Uracil…Uracil is for RNA instead of Thymine)
8) Enzymes: they act as a catalyst
9) Dehydration synthesis vs hydrolysis (???)
10) Pair nitrogen bases from DNA to DNA and DNA to RNA DNA to DNA: Adenine to thymine and cytosine to guanine. EX. Adenine-thymine, guanine-cytosine, adenine-thymine, thymine adenine, cytosine-guanine. *If you know the sequence of one you already know the other
DNA to RNA: adenine-uracil, guanine-cytosine, adenine-uracil, thymine-adenine
Amphipathic – one end loves water, the other hates it
Biochemistry – involves the understanding of life and the chemical processes that govern it
Biosphere – all regions on the earth, and in the atmosphere, where organisms exist
Carbohydrate – a macromolecule that is composed of carbon, hydrogen, and oxygen atoms
Cell – the simplest unit of an organism
Community – assemblage of populations of the same species that occupy the same Environment – “the surroundings or conditions in which a person, animal, or plant lives and hibernates”
Control group - “the group in an experiment or study that does not receive treatment by the researchers and is then used as a benchmark to measure how the other tested subjects do”
Dehydration synthesis – reaction that links subunits (monomers) together to form larger molecules (polymers)
Disaccharide – carbohydrates composed of two monosaccharides (joined by dehydration or condensation reaction; broken apart by hydrolysis) DNA - plays biological roles in coding, decoding, regulation, and expression of genes;
Ecosystem – biotic community of population of different species living in the same place/time
Enzyme – special class of protein catalysts. They increase the rate of a reaction between molecules and move them close enough together to help them react
Hydrolysis – “water-breaking”
Hypothesis – a proposed explanation for a natural phenomenon Lipid – fats and fat like substances composed predominantly of hydrogen and carbon atoms and characterized by their water repellent properties and inability to dissolve in water (hydrophobic)
Macromolecule – large, complex, organic molecules (carbohydrates, proteins, nucleic acids)
Monosaccharide – simplest sugars; most common are 5 or 6 carbons; a type of carbhohydrate
Nonpolar – a nonpolar molecule is a molecule in which the electrons are shared equally between the nuclei and the distribution of charge is even Nucleic acid – DNA and RNA;
Organ – two or more types of tissue combined to perform a common function Organ system – “a group of organs that work together to perform one or more functions; each does a particular job and is made of certain tissues” Organelle – membrane-bound sub-cellular structure with its own unique function
Organic – “natural matter or compounds with a carbon base” Phospholipid – glycerol bonded to 2 fatty acids and a phosphate group; amphipathic molecule with a polar head and a nonpolar tail Polar – charged N+ (?) “a polar molecule has a partial positive charge in one part of the molecule and a complementary negative charge in another part Polysaccharide – carbohydrates composed of many monosaccharides linked together (polymers); energy storage; structural role
Population – group of individuals of the same species that occupy the same environment
Protein – polymers composed of amino acid monomers (20 amino acids with common structure, side chain determines structure and function) RNA - encodes the genetic instructions for the development and function of all organisms
Theory – a broad explanation of some aspect of the natural world; substantiated by a large body of evidence
Tissue – the association of many cells of the same type