BSC1005studyguide - Study Guide for BSC 1005 Exam 1. Chapters 1, 2 and 3. PDF

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Study Guide for BSC 1005 Exam 1.
Chapters 1, 2 and 3....

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BSC1005 – EXAM 1 SCIENTIFIC METHOD - allows the solving of problems and the answering of questions.  Observation    

Measurement Experiment Formulation Testing

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Modification Hypothesis

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Prediction

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HYPOTHESIS - a proposed scientific explanation for a set of observations. Must be testable and falsifiable. Never proven; can only be supported. Becomes a scientific theory when it can be tested and refutable. 

Testable – supported or rejected by carefully designed experiments or

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nonexperimental studies. Falsifiable – can be rules out by data.

SCIENTIFIC THEORY - powerful, broad explanation of a large set of observations. Based on well supported hypothesis. As close to a "law" as Biology gets. Supported by research of several different independent sources. EXPERIMENTAL GROUP - experiences the experimental intervention or manipulation. CONTROL GROUP – experiences no experimental intervention or manipulation. (Basis for comparison). RANDOMIZED CLINICAL TRIAL - randomly chosen subjects used in control and experimental groups to test an independent variable. DEPENDENT VARIABLE – cannot be changed by researcher. 1 AG

INDEPENDENT VARIABLE – can be manipulated by scientist. SAMPLE SIZE – number of experimental subjects or number of times experiment is repeated. The larger the sample size, the more likely it will have statistical significance. STATISTICAL SIGNIFICANCE OR ANALYSIS – measure of confidence that results obtained are real, rather than due to a random chance. CORRELATION – a relation or connection (NOT CAUSATION). PLACEBO – used as a control when testing something. DOUBLE BLIND EXPERIMENT – the administer and subjects don't know who's in each group until after the testing/experiment is over. BIAS – A particular preference or point of view that is personal, rather than scientific. in favor or against. Unfair. PRIMARY SOURCES – original articles or other texts describing a researcher’s new experimental data, observations, results, and/or theories. (Medical Journals) SECONDARY SOURCES – include claims supported by data and citations from other work published in the field. (Books, Internet, Ads…) ANECDOTAL EVIDENCE – Advice based on an individual experience not on experimental data. EVERYDAY THEORY - an idea based on personal experience and knowledge (my soccer team is on a winning streak, I better keep wearing my lucky socks). ______________________________________________________________________________ LIFE 2 AG

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have a common set of biological molecules

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composed of cells can maintain homeostasis can evolve

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require liquid water sense and response to stimuli

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ability to obtain and use energy

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pH LEVELS – measure of hydrogen ion concentration, how basic or acidic a solution is. Less than 7 = acidic; greater than 7= basic; 7= neutral (H20). SOLVENTS – what solutes are dissolved in (ex. Water). SOLUTES – what is being dissolved in the solved (ex. Salt). SOLUTION – solvent + solute.

PROTON

ELECTRON

NEUTRON

positive

negative

neutral

NUCLEUS OF ATOM – protons and neutrons. CARBON – fourth most common element in the universe; second in the human body. COVALENT BONDS – sharing of a pair of electrons between atoms. MOLECULES – form when atoms are linked by covalent bonds. ORGANIC MOLECULES – have carbon-based backbones and at least one CH bond. INORGANIC MOLECULES – lack carbon-based backbones and C-H bonds.

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MACROMOLECULES – large organic molecules, composed of subunits called monomers, monomers link together to form polymer chains. CELLS – smallest subunits of life that can also sometimes be considered living organisms on their own. HOMEOSTASIS – maintaining a stable internal environment. CHARACTERISTICS OF WATER  water can dissolve hydrophilic (likes water)     

water facilitates chemical reactions reactants = solutes in the mixture products = end result of the chemical reaction cohesion = water molecules stick together adhesion = water molecules stick to surfaces

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water moderates temperature water can dissolve acids and bases solid water is less dense than liquid

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universal solvent

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POLAR MOLECULE – water is a polar molecule. O2 is negative and H is positive. NONPOLAR MOLECULE – balanced molecule. Also, more likely to dissolve in oil. HYDROGEN BONDS – bonds that hold water molecules together as a result of its polarity. HYDROPHOBIC – water fearing (ex. Oil). CARBOHYDRATES    

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molecules composed of carbon, hydrogen, and oxygen major source of energy for cells monosaccharides (simple sugars) are building blocks for carbs disaccharides are composed of 2 monosaccharides

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polysaccharides are composed of many monosaccharides

PROTEINS     

polymers of amino acids joined by peptide bonds made up of carbon, oxygen, hydrogen, and nitrogen different combinations of amino acids give proteins different properties enzymes carry out all important actions in cells cell structures, movement of cells, cell replication, structural support, support of cells, communication, and defense

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encoded by DNA genes

LIPIDS  hydrophobic  composed mostly of hydrogen and carbon 

Fat is composed of a glycerol molecule joined with 3 fatty acid tails Steroids are 4 carbon ring structures (cholesterol, estrogen,

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testosterone) Phospholipids are composed of a glycerol molecule, 2 fatty acid tails,

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and a phosphate group NUCLEIC ACIDS  polymers of nucleotides

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nucleotide= sugar + phosphate + nitrogenous base nucleotides are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) structure is a double helix (A-T) (G-C)

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each strand has a sugar phosphate backbone

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ENZYMES – Catalysts for chemical reactions in living things (PROTEINS). DEHYDRATION – An abnormally low amount of water in the body. WHOLE FOODS > PROCESSED FOODS – have not been stripped of their nutritional value. UNSATURATED FATS 

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liquid at room temperature

not bound to as much hydrogen as possible SATURATED FATS 

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fats that are solid at room temperature bound to as much hydrogen as possible

VITAMINS IN THE BODY – enable chemical reactions and regulate body processes, organic substances that act as coenzymes. VITAMIN D – only vitamin our body can synthesize. MACRONUTRIENTS – nutrients that are needed in large amounts. MICRONUTRIENTS – needed in small amounts. ____________________________________________________________________________ PROKARYOTIC CELL – smaller and simpler - no true nucleus. EUKARYOTIC CELL – much more complex - have organelles and a true nucleus.

PROKARY

EUKARY

OTIC

OTIC

nucleus

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organelles

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cell wall

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cell

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cytoplasm

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ribosomes

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membrane

CELL MEMBRANE – surrounds all cells. Made of phospholipids and proteins.  large or hydrophilic molecules cross the membrane by assistance of transport proteins. 6 AG

TRANSPORT PROTEINS

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sit in the membrane bilayer act as a channel, carries, or pump provide passageway

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can move substance with or against concentration gradient.

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ACTIVE TRANSPORT - solutes are pumped from lower concentration to higher concentration with the help of transport proteins. Requires energy. SIMPLE DIFFUSION – flow of molecules down a concentration gradient, across a membrane without help of an intermediary. FACILITATED DIFFUSION – flow of molecules down a concentration gradient; requires help of a protein. No energy required. OSMOSIS – movement of free water molecules across a semipermeable membrane. “Free” as non-interacting particles – such as salt ions. PHOSPHOLIPID BARRIER – hydrophobic tails orient inside the membrane (away from water). SEMIPERMEABLE – some molecules can cross, and some can't. NUCLEUS – surrounded by a double nuclear membrane-- houses DNA. Surrounded by nuclear envelope. DNA - molecule of heredity. RIBOSOMES – a complex of RNA and protein that carry out protein synthesis. MITOCHONDRIA – Extract energy from food and convert it into a useful form; powerhouse of the cell.

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LYSOSOMES – an organelle containing digestive enzymes. (Cell garbage disposal). ROUGH ENDOPLASMIC RETICULUM – involved in protein synthesis and has ribosomes attached to its membrane. SMOOTH ENDOPLASMIC RETICULUM – involved in lipid synthesis and lacks ribosomes GOLGI APPARATUS – a system of membranes that modifies and packages proteins into vesicles for export by the cell. CENTRIOLES – move genetic material during cell division. CYTOSKELETON – network of protein fibers, maintains cell shape, cell movement, and movement of structures within cells. CENTRAL VACUOLE – found in plant cells and manages nutrient storage, waste management, predator deterrence, sexual reproduction, physical support. CHLOROPLASTS - plant cell’s solar power. Sited of photosynthesis. ANTIBIOTICS  chemical that can slow or stop the growth of bacteria  often naturally produced by living organisms 

preferentially kill bacteria without harming human or animal host target prokaryotic cells

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cell walls are rigid due to peptidoglycan

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polymer made of sugars and amino acids o allows bacteria to survive in watery environment - like a pond or your gut o

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penicillin weakens the cell wall bacterial cells fill up with water and burst due to osmosis

GRAM-POSITIVE - cell wall with layer of peptidoglycan that retains the Gram stain. GRAM-NEGATIVE - cell wall layer of peptidoglycan surrounded by lipid membrane that does not retain the Gram stain; prevents penicillin from reaching peptidoglycan underneath. STREPTOMYCIN - another method for killing bacteria  

interferes with prokaryotic ribosomes. leaves eukaryotic ribosomes unaffected.

BMI – Body Mass Index; a measure of body weight relative to height. INSULIN – It aids in the body's use of glucose. a hormone. produced by beta cells of the pancreas. Synthesis and secretion of insulin is made by ribosomes, rough ER, and Golgi apparatus. SALT – inhibits the growth of bacteria because it is hypertonic and causes the bacteria to shrink because water leaves the bacterial cell. PENICILLIN – interferes with cell wall synthesis, causing bacteria to die from swelling and rupturing of the cell. ______________________________________________________________________________

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CHAPTER 1  Science is a process – a way of seeking answers to question on the 

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basis on observations and experiments. Scientists rely on peer-reviewed scientific reports to learn about new advances in the field. Peer review help to ensure that the scientific results are valid as well as accurately and fairly presented. A potential answer to a scientific question is called a hypothesis. Hypotheses are tested in controlled experiments or in observational studies, the results of which can support or rule out a hypothesis. Hypotheses can be supported by data but cannot be proved absolutely, as future studies may provide new findings.

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Every experiment should have a control group – a group that is identical in every way to the experimental group except for one factor: the independent variable.

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The independent variable in an experiment is the one being deliberately changes in the experimental group. The dependent variable is the one measured result of the experiment. Often a control group takes a placebo, a fake treatment that mimics the experience of the experimental group.

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The strength of the conclusion of a scientific study depends on, among other factors, the type of study carried and the sample size.

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Scientific theories are different from everyday theories. A scientific theory has undergone extensive testing, is supported by a significant body of evidence and has never been disproven.

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In epidemiological studies, a relationship between an independent variable and dependent variable does not necessarily means one caused the other; in other words, correlation does not equal causation.

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A randomized clinical trial is one in which test participants are randomly chosen to receive either a standard treatment (or place) or

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an experimental treatment. Most of the general public relies on media reports for scientific information. Media reports are not always completely accurate in how they portray the conclusions of scientific studies.

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To understand a study properly, it is often necessary to look at how the study was designed and to analyze the data oneself.

CHAPTER 2  On Earth, living organisms share a number of fundamental properties: they grow and reproduce, maintain homeostasis, sense and respond to their environment, and rely on energy to carry out their functions. 

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All matter is composed of elements, of which there are 118 known in the universe. Each element has a unique atomic structure, with a particular number of protons, neutrons, and electrons. On Earth, living organisms are made up of organic molecules, which contain a backbone of the element carbon and carbonhydrogen bonds.

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Four types of carbon-based organic molecules make up living things: carbohydrates, proteins, nucleic acids, and lipids.

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Living organisms on Earth are made of cells, which contain water and are bounded by a cell membrane; cells are the smallest unit of life.

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Water is a polar molecule, with the hydrogens carrying a partial positive charge and the oxygen carrying a partial negative charge.

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Because of its partial charges, a water molecule can form hydrogen bonds (weak attractions between these opposite partial charges) with other water molecules and interact with other

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charged molecules. Water has many properties that make it a crucial component of life on Earth, it is a “sticky” it regulates heat well, it floats when frozen,

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and is it a good solvent. When atoms lose or gain electrons, they become ions. Oppositely

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charged ions can form ionic bonds – strong electrical attraction. Water is a good solvent of substances with ionic bonds. Substances that easily dissolve in water, like salt, are considered hydrophilic; substances that do not dissolve in water, like lipids,

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are hydrophobic. The concentration of H+ ions in a solution determines the pH. Most

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chemical reactions in cells take place at a nearly neutral pH. If life is found on other planets, it may or may not use the chemical framework used by life on earth.

CHAPTER 3

12 AG

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Antibiotics are chemicals, originally produced by living organisms, that selectively target and kill bacteria.

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According to the cell theory, all living organisms are made of cells. New cells are formed when an existing cell divide.

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There are two types of cells, distinguished by their structure: prokaryotic and eukaryotic. Prokaryotic cells lack membrane-bound

organelles; eukaryotic cells have a variety of membrane-bound organelles, including central nucleus. 

All cells are enclosed by a cell membrane made up of phospholipids and proteins. Some cells also have a cell wall surrounding the cell membrane that imparts additional strength.

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Water crosses cell membranes by osmosis in order to balance the solutes on each side. In a hypotonic solution, water moves into the cell, causing it to swell; in a hypertonic solution, water leaves the cell,

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causing it to shrivel. Bacteria surrounded by a cell wall containing peptidoglycan, a

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molecule not found in eukaryotes. Some antibiotics, like penicillin, work by preventing peptidoglycan synthesis, weakening the cell wall. All cells have ribosomes, complexes of RNA and proteins that synthesize new proteins. Some antibiotics, like streptomycin, work by interfering with prokaryotic ribosomes.

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The cell membrane is semipermeable: only substances with certain characteristics can cross it freely without help. Small hydrophobic molecules can cross cell membranes by simple diffusion, a process that does not require an input of energy.

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Large hydrophilic, or charged molecules are transported across the membrane with the help of membrane transport proteins.

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Facilitated diffusion is the transport of molecules down a concentration gradient through a transport protein; it does not require

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an input of energy. Active transport is the transport of molecules up a concentration gradient through a transport protein; it requires an input of energy. Eukaryotic cells contain a number of specialized organelles, including a nucleus, endoplasmic reticulum, Golgi apparatus, mitochondria, lysosomes, and chloroplasts, each of which carries out a distinct

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function. Eukaryotic cells likely evolved as a result of endosymbiosis, the engulfing of one single-cell prokaryotic by another....