Unit 1: Ch 1 & 2 Flashcards
List the 25
essential elements
- Oxygen
- Carbon
- Hydrogen
- Nitrogen
- Phosphorus
- Calcium
- Potassium
- Sulfur
- Sodium
- Chlorine
- Magnesium
- Fluorine
- Iodine
- Iron
- Manganese
- Boron
- Chromium
- Cobalt
- Copper
- Molybdenum
- Selenium
- Silicon
- Tin
- Vanadium
- Zinc
List the 4 compounds that make 96%
of the bodyweight of living things
- Carbon (C)
- Oxygen (O)
- Hydrogen (H)
- Nitrogen (N)
Ability to adapt
- Adapt means they are suited to a certain way of life or suited to a certain environment.
- These adaptations are produced by the process of evolution
- Adaptations that result in higher reproductive success tend to increase in frequency in a population from one generation to the next. This change in the frequency of traits in populations and species is called evolution
Amino Acids
- Structure
- Groups
- Bonding
- Structure:
- Contains a central C atom, an amino group (NH2), a carboxyl group (COOH), and a specific R group
- Groups
- Amino Group
- Acidic Group
- R Group
- The R group determines the characteristics (size, polarity, and pH) for each type of amino acid.
- Peptide bonds form between the carboxyl group of one amino acid and the amino group of another through dehydration synthesis
- A chain of amino acids is a polypeptide
Amino Group
- Symbol
- Bonds
- Occurs in
Symbol: -NH2
Bonds: Single covalent bonds
Occurs in: Amino acids, proteins
Animals
- Multicelled
- Obtain energy and materials by ingesting food
- Examples: insects, birds, and humans
Archaea
- Single-celled
- The most primitive living things
- Live in harsh aquatic environments
- High temperature
- No oxygen
- High salt content
Atom
- The least complex level begins with the atom
- An atom is the smallest unit of matter that forms a chemical element
- At the center of an atom is its nucleus, which is composed of protons and neutrons
- An atom is electrically neutral which means the number of protons (positive charges) equals the number of electrons (negative charges)
Atomic mass
(aka atomic mass number)
- Equal to the sum of the protons and neutrons
- The weight of the atom
Atomic number
It is the number of protons in an atom
ATP
- Nucleotide that occurs in muscle tissue
- Is used as a source of energy in cellular reactions and in the synthesis of nucleic acids
- Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions to harness the energy within the bonds of ATP
Key Points
- Adenosine triphosphate is composed of the nitrogenous base adenine, the five-carbon sugar ribose, and three phosphate groups.
- ADP is combined with a phosphate to form ATP in the reaction ADP+Pi+free energy→ATP+H2O.
- The energy released from the hydrolysis of ATP into ADP is used to perform cellular work, usually by coupling the exergonic reaction of ATP hydrolysis with endergonic reactions.
- Sodium-potassium pumps use the energy derived from exergonic ATP hydrolysis to pump sodium and potassium ions across the cell membrane while phosphorylation drives the endergonic reaction.
Bacteria
- Single-celled
- Live everywhere on the planet except in harsh environments
- Are primitive, but not as primitive as Archaea
Compare Biological Macromolecules
List the 12 Levels of
Biological Organization
- Biosphere
- Ecosystem
- Community
- Population
- Species
- Organism
- Organ System
- Organ
- Tissue
- Cell
- Molecule
- Atom
Describe the biosphere
Regions of the earth’s crust, waters, and atmosphere inhabited by living organisms
What is a buffer?
- A buffer is a substance that keeps pH within normal limits
- Buffers resist pH changes because they can take up excess hydrogen ions (H+) or hydroxide ions (OH-)
Describe the polymers in carbohydrates
- Glycogen: found liver & muscle of mammals. Functions as an energy store. It is short term store store of energy. Made of glucose monomers. When body needs glucose, glycogen in liver is broken down into its glucose monomers; the glucose enters the blood for cells to use. When muscles need glucose (such as when you are exercising), the glycogen inside the muscle is broken down into its glucose monomer and the glucose is used to make energy inside the muscle cell
- Starch: found in roots & seeds of plants. Potatoes are an example of a root vegetable that is high in starch. Functions as an energy store (just like with glycogen in animals, when a plant needs glucose for energy, it breaks down glycogen). In plants, glycogen is a long term energy store. Glycogen is made of glucose monomers
- Cellulose: found in (a) the cell wall of plants and found in (b) the bark & stem regions of the plants. Functions to provide structural (physical) support for the plant cell and for the body of the plant. The cell wall protects the plant cell. The stem of a plant allows the plant to stand upright & it connects leaves to the plant. The bark protects the inner tissues of the tree (just like your bones organs in your body)
Carboxyl Group
- Symbol
- Bonds
- Occurs in
Symbol: -COOH
Bonds: Single covalent bonds
Occurs in: Sugars, amino acids, proteins
Describe the following characteristics of carbohydrates:
- Monomers
- Polymers
- Elements
- Structure
- Function
- Monomer: Monosaccharide
- Glucose (blood of mammals)
- Galactose (milk of mammals)
- Fructose (plants)
- Polymer: Polysaccharides
- Glycogen
- Starch
- Cellulose
- Elements: C, H, O
- Structure:
- H to O ratio is 2:1
- The number of carbons usually ranges from 3-7
- Depending on the number of carbons in the sugar, they also may be known as trioses (3 carbons), pentoses (5 carbons), and or hexoses (6 carbons)
- Monosaccharides can exist as a linear chain or as ring-shaped molecules; in aqueous solutions, they are usually found in ring forms
- Function
- Source of energy
- Structural/physical support
- Cell-to-cell recognition
- Cell identification: allows the immune system to recognize/distinguish cells
- Forms part of DNA & RNA
List the 8 categories of classification
- Domain (largest)
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species (smallest)
Cell Theory
All organisms are composed of cells,
and new cells only come from pre-existing cells
Cells
- When two or more organelles with a common structure and function join
- Living matter is always compartmentalized into one or more cells, and all living structures must have cells
- A cell is the smallest unit that can perform all the basic functions of life
Cellulose
- The bonds that hold the glucose molecules together
- They are sturdy and allow fibers to form and build tough cell walls
Central Science
- Chemistry is often called the “central science” because all areas of science rely on some chemical principles.
- Every scientific area from physics to astronomy to ecology/environmental to physical therapy relies on chemistry.
- You need to learn chemistry because chemicals and chemical reactions are part of living things.
Apply the characteristics of life to answer this question:
Is a cut flower living or non-living?
For the cut flower to be considered alive, it must meet each of the following characteristics:
- Order- Living things are organized into discrete structures that are called cells. Yes, the cut flower has cells.
- Require energy and materials- Living things require an outside source of energy and materials to maintain their organization. Cells use energy from nutrients. Yes, the cut flower is able to take in an outside source (i.e., sun, water) to maintain its organization (for a short period of time)
- Reproduce- Living things are able to form new cells within their body. No, the cut flower will not be able to reproduce. Being that it is cut, it does not have its root structure which contributes to other characteristics required to be considered alive.
- Develop- Living things are able to grow during their lifetime. The cut flower may continue developing for a short period of time (i.e. a petal may unfurl), but once the flower is cut away from its root structure it begins to die
- Respond to stimuli- Respond to stimuli, which is an environmental change. Yes, for the time that the cut flower is able to absorb energy, it will be able to respond to stimuli
- Are Homeostatic- Able to maintain stable internal conditions even when external conditions are changing. No, since it no longer has its root structure, it cannot be Homeostatic
- Evolution- Living things have the ability to adapt to a certain environment. The cut flower cannot adapt to its new environment. It no longer has its root structure and it has begun dying. It will ultimately die.
Since the cut flower does not meet each characteristic of life it is not considered to be alive.
List the 7 Characteristics of Life
To be alive, an object must have all of these characteristics. If it lacks just one of them, it is not considered alive.
- Order
- Require Energy & Materials
- Reproduce
- Develop
- Respond to Stimuli
- Are Homeostatic
- Evolution
Chemical bond
- An attraction between atoms
- The attraction holds atoms together to form molecules and compounds
Chemical bond
- An attraction between atoms
- Holds atoms together to form molecules and compounds
Chemical compound
- Atoms containing two or more elements
- Examples: H2O, NaCl, and CO2
Chemical formula
An abbreviation of the elements and atoms present in a molecule
Chemical Formula
- The chemical formula is an abbreviation for the molecule
- Tells us two facts about the molecule:
- The elements present
- The atoms of each element
Describe a community
Interacting populations in a particular area
Compound
- When two or more elements bond together
- Example: H2O
Conclusion
The data is analyzed to determine if the hypothesis was correct.
- Often times, the conclusion leads to another hypothesis and another round of the scientific method
- Based on the results of many experiments using the scientific method, a scientific theory is developed
Control Group
- Part of an experiment that is not subject to the independent variable controlled by the researcher
- 2 types of controls
- Negative Control: expected to have a negative result (no change occurs to them)
- Positive Control: expected to have a positive result
Covalent Bonds
- Forms when atoms share one to three pairs of electrons
- The most common type of bond found in nature
- Covalent bonds can be single, double or triple
- Two types of covalent bonds: polar and nonpolar
Deductive Reasoning
- The use of general principles to predict specific outcomes
- Often uses “if…then” statements
- Moves from general premises to a specific conclusion
- Examples:
- All numbers ending in 0 or 5 are divisible by 5. The number 35 ends with a 5, so it must be divisible by 5
- All birds have feathers. All robins are birds. Therefore, robins have feathers.
- Since today is Friday, tomorrow will be Saturday
Dehydration Reaction
A chemical reaction in which two molecules are covalently linked in a reaction that generates H2O as a second product
Dehydration Synthesis
- When monomers join to create polymers of organic molecules
- Hydrogen is removed from one monomer and a hydroxyl group (-OH) is removed from another monomer, forming water
Explain denature
- When a protein is denatured, its shape and properties change, and it usually cannot function anymore
- Proteins can be denatured by exposing them to pH changes (acids or bases) or by exposing them to extreme temperatures (either hot or cold)
- Example: Frying an egg. Egg white starts out as clear and liquid, the extreme heat changes the egg white to opaque and a rigid texture
Develop
Changes that occur during an organism’s lifetime
Distinguish between the different
Disaccharides
-
Maltose: Glucose + Glucose
- Found in grain plants like wheat & barley and products like beer & malted milk which are made from grains
-
Sucrose: Glucose + Fructose
- Found in plants especially sugar cane & sugar beets. Sucrose is known as “table sugar” and is used to sweeten foods and beverages
-
Lactose: Glucose + Galactose
- Found in milk of mammals. Lactose is known as milk sugar
DNA
- Provides the instructions for the organization and metabolism of an organism
- Functions as the hereditary material of all living things
- Located in the nucleus of a cell
- Double-stranded helix
What is the monosaccharide in DNA?
Deoxyribose
Domain
Domain is the largest category and contains the most members
List the 3 domains of living things
- Archaea
- Bacteria
- Eukarya
Double-blind study
When neither the researcher or test subject knows whether they are receiving a placebo or treatment
Describe ecosystem
A community plus its physical environment
Electron
- Determines the chemical properties of an atom
- Found on the periphery, or on the side of an atomic structure
- Electron shell, which is a more specific way to determine where an electron is housed; or
- Electron cloud, which is a more general way of showing where an electron is
- Carry a single negative charge
- Notated with a lowercase “e”
Electron Shell
Indicates the average location of electrons
Electron shell
- Electrons are located in electron shells that surround an atom
- The number of electron shells an atom has depends on the total number of electrons
- Each shell holds a limited number of electrons:
- Shell 1 holds 2 electrons
- Shell 2 holds 8 electrons
- Shell 3 holds 8 electrons
- Shell 4 holds 8 electrons
Electronegativity
A measure of an atom’s ability to attract the shared electrons of a covalent bond to itself.
If atoms bonded together have the same electronegativity, the shared electrons will be equally shared and will become anions.
Electropositivity
The tendency of an atom to donate electrons and form positively charged cations
Element
- An element is a pure substance that cannot be broken down into smaller substances with different properties by ordinary chemical means
- Each element has its own unique properties such as density, solubility, melting point, and chemical reactivity
What is an emulsifier?
- Contains molecules with a nonpolar end and a polar end, and results in fat or oil dispersing in water
- Examples:
- The detergent used to wash clothes
- Creamy salad dressing
Endergonic Reaction
An endergonic reaction is a reaction in which energy is absorbed.
This means that the net change in free energy is positive. There is more energy in the system at the end of the reaction than at the beginning of it.
Energy & Materials
Living things take in molecules from the environment and chemically change them into molecules that form their own structures, control their physiology, or provide them with energy
Enzymes
- A group of proteins that lower the amount of energy required to perform a chemical reaction
- Enzymes are not consumed in a chemical reaction
- Without enzymes, our reactions would take too long to support life