Sabrina's Chapter 1-3 Notecards Flashcards
What is the basic unit of matter?
An atom
List the levels of organization of life from smallest to largest
Atom, Molecule, Cell, Tissue, Organ, Organ System, Organism (Species), Population, Community, Ecosystem, Biosphere
What is the difference between an atom and a molecule?
Atoms combine to form molecules and molecules form the structures within the cell.
What is the most basic unit of life?
A cell
Define a tissue
Similar cells grouped together that have a common function
Define an organ
Different types of tissues that work together to perform a function
Define an organ system
Organs that work together to perform a common function
Define species
A group of similar, interbreeding organisms
Define a population
A species in a particular area
Define a community
Interacting populations in a particular area
Define an ecosystem
A community and the physical environment
Define a biosphere
Regions of the Earth’s crust, waters, and atmosphere (inhabited by living organisms)
True or False: Energy cycles
False
How does energy flow between organisms?
Producers receive energy from the sun and combine it with inorganic chemicals through photosynthesis. Smaller consumers then receive energy from the producers. Larger consumers receive energy from the smaller consumers.
When energy flows between organisms it is lost as?
Heat
True or False: Chemicals cycle between organisms?
True
How do chemicals cycle between organisms?
Producers take in solar energy and combine it with inorganic nutrients to produce organic nutrients through photosynthesis. Consumers eat the producers and eventually die. Decomposition returns the inorganic nutrients to the ground and eventually back to the producers.
What must happen in order for organic molecules in the food chain to be returned to the producers?
Death and decomposition
Where does all the energy necessary for life come from?
The sun
Define homeostasis
A state of biological balance
List the three most common ways to maintain homeostasis
Temperature, Moisture level, and Acidity
What is the most common way organisms respond to their environment and other organisms?
Movement
Because we know life only comes from life, we know that organisms?
Reproduce
How do multicellular organisms reproduce?
The joining of the sperm from a male and the egg from the female
How do single celled organisms reproduce?
They split into two new individuals
Define a gene
The genetic instructions of DNA
Define mutation
Inheritable changes in the genetic information
Give an example of mutations
Hair/Eye color
How are adaptations related to mutations?
Mutations form an important source of variation in population. This allows organisms to adapt to their environment in order to survive.
How are adaptations related to evolution?
Adaptations are unintentional and provide a framework for evolution.
Define evolution
The way a population of organisms changes over the course of many generations to become more suited to their environment
Define natural selection
The process that makes modifications/adaptations possible
Who is the scientist who developed the theory of natural selection?
Charles Darwin
Define taxonomy
Discipline of identifying and grouping organisms following certain rules
Define systematics
Study of evolutionary relationships
List the basic classification groups from most inclusive to least inclusive
Kingdom, Phylum, Class, Order, Family, Genus, Species
List the basic classification groups from least inclusive to most inclusive
Species, Genus, Family, Order, Class, Phylum, Kingdom
Name the three domains
Bacteria, Archaea, Eukarya
Define prokaryotes
Lack a true nucleus (membrane-bound nucleus)
Which two domains contain prokaryotes?
Bacteria and Archaea
How are bacteria different from archaea?
Archaea arrange their DNA differently than bacteria. Chemicals in archaea’s cell wall and membrane are more similar to eukaryotes
Define eukaryotes
Organisms with cells that have a true nucleus (membrane-bound nucleus)
Which domain contains eukaryotes?
Eukarya
Define binomial nomenclature
A two part name given to all living organisms. The first word is the genus and the second word in the species
What is the correct way to write a binomial nomenclature?
The genus or first word is capitalized. The Species or second word is lower case. The name is always italicized.
Describe the scientific process
The scientific process starts with observations. After gathering background information and making careful observations a hypothesis is formed. The hypothesis is tested through experimentation. After experimentation has concluded, the data should be analyzed and a conclusion should be drawn.
Which part of the scientific method uses inductive reasoning?
Forming a hypothesis
Which part of the scientific method uses deductive reasoning?
The experimental process
In general what is the difference between inductive and deductive reasoning?
Inductive reasoning involves creative thinking and deductive reasoning follows the “if…then” form
Define experimental (independent/manipulated) variable
What is being changed in an experiment
Define responding (dependent) variable
What is being measured or observed in an experiment
Define control variable
The group that is not exposed to the experimental variable in an experiment
True or False: The responding variable of an experiment goes on the X-axis?
False. The responding variable goes on the Y-axis
True or False: The experimental variable of an experiment goes on the X-axis?
True
What is a model organism?
An organism such as a fruit fly or mouse that have been studied extensively
Why are model organisms important?
There is a lot of background information on these organisms so predictions will be easier to make and hypothesis will be easier to test
Describe what it means for an experiment when p
There is less than a 5% risk that the differences are due to chance alone (95% confident that differences are not due to chance)
What is the difference between a scientific journal and a scientific magazine?
A scientific journal contains detailed accounts of an experiment and are peer reviewed while a scientific magazine are an organization of interesting science by reporters
Define scientific theory
When many related hypotheses have been tested by many experiment and are supported by the data collected
Define matter
Anything that takes up space and has mass
Define element
A substance that can not be broken down into a simpler substance by ordinary chemical means
What six elements make up 95% of the body of all living organisms?
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur
What are the three subatomic particles?
Protons, Neutrons, and Electrons
What is the mass of a proton?
1 AMU
What is the mass of a neutron?
1 AMU
What is the mass of an electron?
0 AMU
What is the charge of a proton?
Positive
What is the charge of a neutron?
No charge
What is the charge of an electron?
Negative
Where is a proton found within an atom?
The nucleus
Where is a neutron found in an atom?
The nucleus
Where is an electron found in an atom?
Orbitals in electron shells around the nucleus
What does the atomic number represent?
Number of protons in the nucleus
What does the atomic mass represent?
Sum of the protons and neutrons in an atom
Define an atomic symbol
1 or 2 letters representing the element
What is an isotope?
Elements with the same number of protons but different numbers of neutrons
Define radioactivity
The release of energy and/or particles from the nucleus
Describe the Bohr model of an atom
Shows electrons in orbitals around the nucleus
When electrons fill shells, how many will fit in the first shell/orbital?
2 electrons
After the first shell/orbital is filled, how many electrons will fit in the second/remaining shells/orbitals?
8 electrons
Filling electron orbitals follows what rule?
Octet rule
What is a valence shell?
The outermost shell of an atom
What is a valence electron?
The electrons in a valence shell
Which part of the atom is the only part that participates in forming bonds with other atoms?
The valence shell
Define metabolism
Sum total of chemical reactions in an organism
Define compound
When two or more atoms bond together
What does a molecular formula tell you?
The kind of atoms and number of each atom
What is necessary for covalent bonds to form?
Electrons of an element can be completely lost or gained
Describe ionic bond formation in detail using NaCl as an example
Na (sodium) loses an electron and becomes Na+, Cl (Chloride) gains an electron and becomes Cl-, Na+ attracts Cl- and NaCl is formed
What is necessary for covalent bonds to form?
Atoms must share electrons
Why are the bonds in a water molecule polar covalent bonds?
The oxygen atom in water is much larger than the hydrogen atoms causing the electron density to be shared unequally resulting in a polar covalent bond
How do the polar covalent bonds in water make hydrogen bonds between water molecules possible?
The partially positive hydrogen attracts negative charges and the partially negative oxygen attracts positive charges.
Define calorie
Heat energy needed to raise 1 gram of water 1 degree Celsius
Describe why water has a high heat capacity
Organisms living in water can maintain temperature homeostasis because the temperature of the water does not change rapidly
Define solution
Liquid with dissolved substances
Define solute
A substance that is dissolved in a liquid
Define hydrophilic
Molecules that interact with water
Define hydrophobic
Molecules that do not interact with water
What is the difference between a hydrophilic and hydrophobic molecule?
Hydrophilic molecules interact with water and hydrophobic molecules do not interact with water
Why does ice form on top of liquid water rather than under it?
Ice is less dense than liquid water. When the temperature is below four degrees Celsius, hydrogen bonds become stiff and leave more space between molecules.
Describe the formation of a hydrogen ion from a hydrogen atom
A hydrogen ion is formed when the electron orbiting the atoms nucleus is released/given away
In terms of number of hydrogen ions, describe the pH scale
The larger the amount of hydrogen ions in an element, the lower the pH value. The smaller the amount of hydrogen ions in an element, the higher the pH value.
What does it mean to be acidic?
In order to be acidic an element must have a pH level of 1-6. This element must also have more hydrogen ions than hydroxyl groups
What does it mean to be basic/alkaline?
In order for an element to be basic/alkaline, the element must have a pH level of 8-14. The element must also have more hydroxyl groups than hydrogen ions.
True or False: Hydrochloric acid is a strong acid?
True
Why is Hydrochloric acid so strong?
Hydrochloric acid is strong because it’s two components, hydrogen and chloride, are both extremely stable.
What two things can make a solution a base?
A solution can become a base by either taking up/bonding to hydrogen ions or releasing hydroxyl groups
What is the pH of a neutral solution?
pH 7
What is the pH of an acidic solution?
ph of 1-6
What is the pH of a basic/alkaline solution?
ph of 8-14
What does a buffer do?
A buffer can take up hydrogen ions if there is a lot of acid or take up hydroxyl groups if there is a lot of base
What makes a molecule an organic molecule?
They must be compounds that contain both carbon and hydrogen atoms.
Name the four categories of organic molecules
Carbohydrates, Lipids, Proteins, Nucleic acids
Which element creates the backbone for organic molecules?
Carbon
Why is carbon a good fit to create the backbone for organic molecules?
It can create four covalent bonds with other carbon atoms, hydrogen, nitrogen, oxygen, phosphorous, and sulfur
Define hydrocarbon
Molecules that have a carbon backbone and make the rest of the bond with hydrogen atoms
Define functional groups
When atoms are joined by bonds that create electron clouds that can be reactive they form function groups
How are molecular formulas different from structural formulas?
Molecular formulas tell us what the atomic symbol and the number of each atom while structural formulas tell us how the atoms are bonded to one another
Define isomer
Two molecules that have the same molecular formula but different structural formulas
What is a dehydration reaction (synthesis)?
Condensation reaction that removes a hydrogen atom from one side of the bond and a hydroxyl group from the other side of the bond
Define hydrolysis
Adding water to break a bond
What is the difference between a monosaccharide and a disaccharide?
A monosaccharide is a single carbohydrate molecule while a disaccharide is two monosaccharides joined by a dehydration reaction.
What are the two main functions of polysaccharides (sugars)?
Energy storage molecules or structural molecules
What is the glucose storage molecule in plants?
Starch
What is the glucose storage molecule in animals?
Glycogen
What makes starch different from glycogen?
Starch creates a different branching pattern than glucose
In a carbohydrate, what is the ratio of carbon to hydrogen to oxygen atoms?
1:2:1
What is the difference between a pentose sugar and a hexose sugar?
Pentose sugars have five carbons while hexose sugars have six carbons
How many carbon molecules does glucose have?
Six carbons
Name the three different structural carbohydrates
Cellulose, Chitin, Peptidoglycan
Describe Cellulose
Cellulose is the most abundant carbohydrate and most abundant organic molecule on Earth. Cellulose is created by complex bonds formed between chains of glucose molecules.
Describe Chitin
Chitin is composed of glucose attached to an amino group. It’s found in fungal cell walls, exoskeletons of crabs, lobsters, scorpions, and insects, and seed coatings. Animals cannot digest chitin.
Describe Peptidoglycan
Peptidoglycan is composed of saccharine monomers that are attached to animo acid chains.
What do animals lack that make them unable to digest cellulose and chitin?
Animals lack the enzymes necessary to digest cellulose and chitin.
Where is a Peptidoglycan found?
Bacterial cell walls
What is a fat molecule?
A lipid
What are the parts of a triglyceride?
Three fatty acid chains and one glycerol
Describe how the parts of triglyceride are joined together using a dehydration reaction
A hydrogen ion is lost from each carboxyl group of each fatty acid and a hydroxyl group is lost from each carbon of glycerol
What is the difference between a saturated fatty acid chain and an unsaturated fatty acid chain?
Saturated fatty acid chains are saturated with hydrogen atoms everyone a carbon atom can form a bond with hydrogen. Saturated fatty acid chains are straight and can stack tightly. Unsaturated fatty acid chains have some of the carbons double or triple bonded to adjacent carbon molecules. Unsaturated fatty acid chains are kinky and do not allow for tight stacking.
What organisms make oils?
Plants
Define Glycerol
A three carbon compound with three hydroxyl functional groups
What are the parts of a phospholipid?
Glycerol, two fatty acid chains, one phosphate functional group
Where are phospholipids found?
Membrane surrounding the nucleus in organisms in the Eukarya domain
True or False: Steroids are lipids?
True
Describe the structure of a steroid molecule
Lipids formed into ring structures
What is cholesterol?
A steroid
Where is cholesterol found?
Cell membrane
Proteins are polymers of what molecule?
Amino acid molecules
The central carbon of an amino acid is bonded to four things. What are they?
Amino functional group, hydrogen atom, carboxylic acid functional group, “R” group
Describe three ways “R” groups can behave differently from one another
Nonpolar, Polar, Ionized
What type of covalent bond joins amino acids together?
Peptide bonds
What is the primary structure of a protein?
Amino acid sequence
What is the secondary structure of a protein?
In a secondary structure a protein can twist into a helix or fold into a sheet
What is the tertiary structure of a protein?
Many proteins are globular in shape
What is the quaternary structure of a protein?
More than one string of primary structure sometimes must interact to form a functional protein
What do chaperone proteins do?
Assist in twisting and folding proteins correctly
What are the three parts of a Nucleic acid molecule?
Phosphate functional group, five carbon sugar (deoxyribose/ribose), nitrogen containing base
Describe the structure of DNA
DNA is a double stranded molecule
How many strands does DNA have?
Two
What covalent bonds create the strands in DNA?
A phosphate group of one molecule covalently bonds to the third carbon of the five carbon sugar in the adjacent molecule
What type of bonds join the strands of DNA together?
Two strands are held together by hydrogen bonds between nitrogen containing bases from one strand interacting with nitrogen containing bases in the other strand
What five carbon sugar is DNA composed of?
Deoxyribose
What nitrogen containing bases are DNA composed of?
Adenine, Guanine, Thymine, Cytosine
Describe the structure of RNA?
Single stranded molecule
How many strands is DNA composed of?
One
What covalent bonds create the strands in RNA?
A phosphate group of one molecule covalently bonds to the third carbon of the five carbon sugar in the adjacent molecule (same as DNA)
What five carbon sugar is RNA composed of?
Ribose
What nitrogen containing bases is RNA composed of?
Adenine, Guanine, Uracil, Cytosine
True or False: ATP is a Nucleic acid?
True
What is the function of ATP in living organisms?
High energy molecule that is used to power cellular processes
What is the relationship between ATP and ADP?
Enzymes break the terminal phosphate group bond to release energy and create ADP. A metabolic pathway lines up enzymes that harness energy to create a bond between ADP and a phosphate group to replenish ATP.
