Bio: Midterm

pain and suffering

Archaea

Domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan

Bacteria

single-celled organisms that lack a nucleus; prokaryotes

dependent variable

a variable whose value depends upon independent variable

eukaryotic cell

A type of cell that has a membrane-enclosed nucleus and other membrane-enclosed organelles. All organisms except bacteria and archaea are composed of eukaryotic cells.

eukarya

Domain of all organisms whose cells have nuclei, including protists, plants, fungi, and animals. Includes all eukaryotic organisms

homeostasis

A state of balance among all the body systems needed for the body to survive and function correctly.

hypothesis

a testable explanation for a set of observations based on the available data

independent variable

a variable that stands alone and isn't changed by the other variables you are trying to measure.

organelle

A membrane-enclosed structure with a specialized function within a cell.

prokaryotic cell

A type of cell lacking a membrane-enclosed nucleus and other membrane-enclosed organelles; found only in the domains Bacteria and Archaea.

theory

widely accepted idea that is broader in scope than a hypothesis, generates new hypothesis and is supported by a large body of evidence

adhesion

attraction between different kinds of molecules

cohesion

the sticking together of molecules of the same kind, often by hydrogen bonds

covalent bond

type of strong chemical bond in which 2 atoms share 1 or more pairs of valence electrons

polar covalent bond

covalent bond between atoms that differ in electronegativity. the shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive

unequal sharing of electrons

nonpolar covalent bond

type of covalent bond in which electrons are shared equally between 2 atoms of similar electronegativity

electronegativity

attraction of a given atom for the electrons of a covalent bond

evaporative cooling

process in which the surface of an object becomes cooler during evaporation, a result of the molecules with the greatest energy changing from the liquid to gaseous state.

hydrogen bond

type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in 1 molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule

ionic bond

chemical bond resulting from the attraction between oppositely charged ions

surface tension

measure of how difficult it is to stretch/break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules

dehydration synthesis

the creation of larger molecules from smaller monomers where a water molecule is released

denaturation

in which a protein unravels, losing its specific structure and hence function -- can be caused by changes in pH/salt concentration/high temperature

enzymes

macromolecule, usually a protein that serves as a biological catalyst, changing the rate of a chemical reaction without being consumed by the reaction

hydrolysis

chemical reaction that breaks bonds between 2 molecules by the addition of water; process by which polymers are broken down and an essential part of digestion

hydrophilic

“water-loving” pertaining to polar/charged molecules (or parts of molecules) that are soluble in water

hydrophobic

“water-fearing” pertaining to nonpolar molecules (or parts of molecules) that do not dissolve in water

monomer

the subunit that serves as a building block of a polymer

phospholipids

liquid made up of glycerol joined to 2 fatty acids and a phosphate group, giving the molecule 2 nonpolar hydrophobic tails and a polar hydrophilic head

peptide bond

the covalent bond between two amino acid units in a polypeptide, formed by a dehydration reaction

polymer

large molecule consisting of many identical/similar monomers linked together by covalent bonds

central vacuole

in a plant cell, a large membranous sac with diverse roles in growth and the storage of chemicals and wastes

chloroplast

organelle found in plants and algae that absorb sunlight and uses it to drive the synthesis of organic compounds (sugars) from carbon dioxide and water

cytoskeleton

network of protein fibers in the cytoplasm of a eukaryotic cell, includes microfilaments, intermediate filaments and microtubules

endoplasmic reticulum (ER)

extensive membranous network in a eukaryotic cell, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosom-free (smooth) regions

golgi apparatus

organelle in eukaryotic cells consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum

lysosomes

digestive organelle in eukaryotic cells; contain hydrolytic enzymes that digest engulfed food/damaged organelles

mitochondrion

organelle in eukaryotic cells where cellular respiration occurs. Enclosed by two membranes, where most of the cells ATP is made

nucleus

the atoms central core, containing proteins and neutrons.

\
the organelle of a eukaryotic cell that contains the genetic material in the form of chromosomes, made of chromatin

ribosomes

cell structure consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm.

vesicles

sac made of membranes in the cytoplasm of a eukaryotic cell

activation energy

amount of energy that reactants must absorb before a chem reaction will start

active site

part of an enzyme where a substrate molecule attatches, typically, a pocket or groove on the enzymes surface

aquaporin

transport protein in the plasma membrane of an animal, plant, or microorganism cell that facilitates the diffusion of water across the membrane (osmosis)

induced fit

change in shape of the active site of an enzyme, caused by entry of the substrate so that it binds the substrate snugly.

osmosis

diffusion of free water across a selectively permeable membrane

osmoregulation

homeostatic maintenance of solute concentrations and water balance by a cell organism

selective permeability

property of biological membranes that allows them to regulate the passage of substances across them

substrate

a specific substance (reactant) on which an enzyme acts. each enzyme recognizes only its specific substrate/substrates of the reaction it catalyzes

controlled experiment

An experiment in which an experimental group is compared with a control group that varies only in the factor being tested. -- only one variable is changed

x axis

which axis is the independent variable on?

y axis

which axis is the dependent variable on?

school of fish, ant colony, heart pumping blood, flock of starlings, human consciousness

what are some biological examples of emergent properties?

surface tension of water, structure of diamond, hurricane

what are some non-biological examples of emergent properties?

**Order** - All living things are highly organized, all made up of cells

**Reproduction** - Living things can reproduce themselves to create new organisms

**Growth and Development** - Organisms grow based off of their DNA

**Energy Processing** - Some organisms eat, others capture energy from the sun. Energy is required for organisms' metabolic activities

**Regulation** - Organisms maintain internal conditions through homeostasis, despite environmental changes

**Response to Environment** - Organisms can respond to changes in their environment. (Plants turn towards sun, people pull their hand away from a flame)

**Evolutionary Adaptation** - Natural selection - genetic makeup of population changes over time. Traits that provide benefit to species as a whole will develop over time.

what are the 7 characteristics of life?

cohesion

the sticking together of molecules of the same kind, often by hydrogen bonds

adhesion

attraction between different kinds of molecules

* water is less dense as a solid than liquid because of hydrogen bonding
* when water freezes, each molecule forms a stable hydrogen bond with its neighbors

how does ice float?

* thermal energy in transfer from a warmer to a cooler body of matter (heat)
* thermal energy is the energy associated with the random movement of atoms and molecules

how does water moderate temperature?

it is capable of dissolving more substances than any other liquid.

how is water the solvent of life?

carbohydrates

member of the class of biological molecules consisting of single-monomer sugars (monosaccharides), 2 monomer sugars (disaccharides), and polymers (polysaccharides)

lipids

organic compound consisting mainly of carbon and hydrogen atoms linked by nonpolar covalent bonds, making the compound mostly hydrophobic

proteins

functional biological molecule consisting of one or more polypeptides folded into a specific 3 dimensional surface

nucleic acid

polymer consisting of many nucleotide monomers; serves as a blueprint for proteins and through the actions of proteins, for all cellular structures and activities, the 2 types of nucleic acids are DNA and RNA

Primary - Sequence of amino acids

1st Level of a Protein Structure

Secondary - Interactions of backbone

Second level of Protein structure

Tertiary - Due to side chain interactions (3d shape)

Third level of protein structure

Quaternary - Arrangement of multiple polypeptide chains

Fourth level of protein structure

* Plasma Membrane
* Cytoplasm
* Ribosomes
* DNA (one or more chromosomes)

what are the requirements to be a cell?

* Chloroplast
* Cell wall (cellulose)
* Central vacuole
* Plasmodesmata

Which structures do plant cells have that animal cells do not?

* Carry out genetic control.
* Manufacture, distribute, and breakdown molecules.
* Energy processing.
* Movement, structural support, and communication between cells.

what are the four functional categories of eukaryotic organelles?

transport proteins

regulate movement of molecules in/out of cells

glycoproteins (cell ID proteins)

cell recognition

enzymes

catalyze biochemical reactions

receptor proteins

bind to external signals/relay messages

attachment protein

support membrane/coordinate external & internal

junction protein

\n intercellular connection

active transport

movement of a substance across a biological membrane against its concentration gradient, aided by specific transport proteins and requiring an input of energy. (often as ATP)

passive transport

diffusion of a substance across a biological membrane, with no expenditure of energy

diffusion (passive transport)

random movement of particles that results in the net movement of a substance down the concentration gradient from a region where it is more concentrated to less concentrated

osmosis (passive transport)

diffusion of free water across a selectively permeable membrane

facilitated diffusion

\n passage of a substance through a specific transport protein across a biological membrane down its concentration gradient

endocytosis (active transport/bulk transport)

cellular uptake of molecules/particles via formation of new vesicles from the plasma membrane

exocytosis (active transport/bulk transport)

movement of materials out of a cell by the fusion of vesicles with the plasma membrane

isotonic

\n referring to a solution that, when surrounding a cell, causes no net movement of water into/out of a cell

hypertonic

a solution that causes the cell to lose water

hypotonic

a solution that causes the cell to take in water

tonicity

ability of a solution surrounding a cell to cause that cell to gain or lose water

to obtain the potential energy stored in the bonds of organic molecules and bank this energy in ATP molecules

whats the basic purpose of cellular respiration?

Hydrolysis vs. Dehydration Synthesis

Dehydration Synthesis - Water is released to form larger molecules

Hydrolysis - Water is added to break apart larger molecules

Types of Microscopes

**SEM** - Surface electron microscope. Light doesn't pass through object, but it shows a 3D picture of the surface

**TEM** - Transmission electron microscope. Light passes through a thin layer of object

**Light** - Light passes through thin layer of object (shows color).

Three Tenets of Cell Theory

* All organisms are composed of cells (unicellular, multicellular)
* The cell is the structural functional unit of life
* All cells arise from preexisting cells