BIO 2 unit 1 pt.1: living systems, water

All living organisms

• are composed of 1 or more membrane bound cells

• are able to reproduce

• are the products of evolution

• store, process, and transmit information—genetic and enironment sensing and responses

• acquire and use energy

Theory

an explanation for a very cenergal calss of phenomena or observations that are supported by a wide body of evidence

• ex: cell, evolution, and chromosomes as units of inheritance

proven, disproven

Theories cannot be ___ but can be ____

Cell theory

all organisms are made of cells

• what organisms are made of

pre existing

cells are produced by the division of ____ cells

unicellular

organisms made up of a single cell

multicellular

organisms are made up of multiple cells

cell

• separated from the environment by a clear boundary (plasma membrane)

• contains genetic information (molecule(s) of DNA)

• obtains and uses energy and matter to power its activities and build or repair its components

all cells

• have a cytoplasm surrounded by a plasma membrane

• contain DNA

• contain ribosomes

phospholipids

plasma membranes are made up of ____

fluid mosiac model

the plasma membrane is considered a ___ with proteins—peripheral, integral, chloesterol channel—, carbohydrates, glycoproteins and glucolipids

before kernal

prokaryote

true kernal

eukaryote

Prokaryotic cells

• unicellular

• cells do not have internal comparments or organelles surrounded by membranes

• Bacteria and archaea domains

• cell wall in addition to plasma membrane

• no nucleus

  • DNA in a single circular molecule/chromosome in nucleoid region

• small

Eukaryotic cells

• up to 100x than prokaryotic cells

• contain organelles-specialized and defined by membranes— and membrane networks

• nucleis contains DNA in multiple, linear molecules (chromosomes

• Domain Eukarya—kingdoms: protists, fungi, plants, animals (can be both unicellular or multicellular)

asexual, prokaryotic

binary fission

asexual, eukaryotic

mitosis

sexual, eukaryotic

meiosis

meiosis

reproduction that produces diversity

Theory of inheritance

DNA is organized into chromosomes and DNA is inherited through cell division—before cell divion occurs, all chromosomes in a cell are replicated (copied) and evenly distibuted to the daughter cells

• how is hereditary information transmitted from one generation to the next

chromosomes

a structure consisting of a single, long molecule of DNA

one

all your cells contain ___ copy of the same DNA (genome)

genes

segments of DNA

genes

DNA is organized into ____

codes

a gene ___ for a product—RNA or protein— that severs a function in the cell

transcription, translation, amino acid chain and fold into a protein

DNA to protein

phenotype___traits

functions performed by RNAs and proteins determine ___ or ____ of an organism

endosymbiosis

we hypothesize that the first cells are prokaryotes (bacteria and archaea) and that eukaryoties arose by ___

endosymbiosis

certain bacteria beame engulfed by archaea and remain within the host cell, forming the first organisms

Last universal common ancestor

all things are related and ultimately derived from 1 initial living organism

shared ancestry

___ explains structural similarities across domains and kingdoms of life

Ex: ribosomes of archaea, bacteria, and eukaryotes contain come identical core structural elements

theory of evolution

explains variation and diversity

• where do organisms come from

evolution

the process by which populations and species change and diversify over long periods of time

ex: mutation and natural selection

mutation

a change in the genetic code

passed, accumulate

genetic variants (mutations) that result in phenotypic changes can be ___ and ____ over many generations—descent with modification

natural selection

individual that have genetically determined traits that increase their fitness in eviionments have increased likelihood of reproduction and passing their genes on to their offspring

• frequences of genes and the traits they determine increase population over couse of generations

• adaption

adaption

traits that become common because they increase the fitness of organisma

shared ancestry

living things are classified into groups based on ____

energy, matter

living systems exchange ___ and ___ with their environment

transformed

to produce a change, energy must be ___

energy

capacity to do work

• in many different forms

chemical potential energy

energy contained within the chemical bonds of molecules

kinetic energy

the energy of motion

• include thermal/heat, sound, and electromagnetic

photosynthesis

allows living organisms to capture the sun’s energy

• provide energy for photosynthetic organisms

• provides energy for organisms that eat photosynthetic organisms

grow, do work

everytime organisms get energy from the environment they turn it to a form they can use to ___ and ___

returned, heat

with each transformation of energy, a portion of energy is ___ to envrionment as ____

first law of thermodynamics

energy cannot be created or destroyed, it can only be transformed (converted) from 1 form to another

• the total energy in the universe is constant

second law of thermodynamics

the amount of disorder (entropy) in the universe tends to increase

• when an energy transformation occurs there is an increase in entropy

low

living things are highly organized and therefore have __ entropy

energy

___is needed to maintain organization and to do work, which is why disorder is more likely than order

photosynthesis

6 CO₂ + 6H₂O -light→ C₆H₁₂O₆ + 6 O₂

cellular respiration

C₆H₁₂O₆ + 6 O₂ → 6 CO₂ + 6H₂O + 38 ATP

elements

pure substances that cannot be further broken down

• made up of its own type of atom

• composed of p, e, n

nucleus, positive

protons and neutrons are found in the ____, and have an net ____ charge

cloud/orbital

electrons move in a ____ around the nucleus

neutral

the overall charge of an atom is ___

atomic number

number of protons

• distinct number for every element

mass number

number of protons and number of neutrons

isotopes

atoms of the same element that have a different number of neutrons and therefore different masses

equal

atoms are uncharged, so the number of protons ___ the number of electrons

orbitals

the areas around the nucleus where electrons are most likely to be found

electron shells

levels that orbitals are grouped to

• each shell contains a specific number of orbitals

2

orbitals can hold up to ____ electrons

caton

positively charged ion

anion

negatively charged ion

ionic bond

interaction between cation and anion

covalent bond

a chemical bond in which two atoms share a pair of electrons

• for full valence

electronegativity

the tendency of an atom attract electrons

• important for water

• affect interactions—a covalent bond may share electrons equally or unequally depending on how strongly they attract electrons

O, N, C=H

electronegativity values greatest to least

nonpolar covalent bonds

atoms share electrons equally

polar covalent bond

atoms share electrons unequally

• partial charges

equal, neutral

partial charges across a covalent bond are ____ and opposite to one another, causing the atom to be overall ___

hydrogen bond

a weak attraction between a hydrogen atom with a partial charge (in a molecule) and an atom with a partial negative charge (in another molecule)

• rep with dotted lines

• water!

solvent

water is an excellent _____

surrounds, breaks, ions

when NaCl is poured into water, water ____ the molecule and ___ the bond, forming ____

70

a cell is made up of ____% of water

covalent, intact, hydrogen, water

when you pour glucose into water, the ____ bonds remain ___ the partially charged atoms on surface of glucose molecule form ____ bonds with ___ molecules

hydrophilic molecules

• can be dissolved in water

• may be charge (like Na+)

• may be uncharged but with a partial charge resulting from a polar covalent bond (ex: glucose)

hydrophobic molecules

• cannot be dissolved in water

• have few or no partially charged atoms because they have many nonpolar covalent bonds

• tend to aggregate with each other and exclude water

cohesion

the tendency of water molecules to stick to one another

• why water forms droplets

  • H-bonding

adhesion

the tendency of water molecules to stick to other molecules

• water and a solid surface

• meniscus

surface tension

special type of cohesive force caused by attraction between molecules at the surface of a liquid

• minimize total surface area

• causes water to resist any force that increases its surface area

elastic membrane

the surface area of water acts like an ___

spontaneously

the covalent bons of water molecules can dissociate ____

pH

describes the concentration of H⁺ (free protons in an aqueous solution)

7

pH of ___ is neutral, and is based on water proton concentration—the reference point

base

• pH>7

• any substance that combines with H+ dissolved in water, and lowers the H+ concentration, increasing the pH

• proton acceptor

acid

• pH<7

• any substance that dissociates in water, releasing H+

• proton donor

• the stronger it is, the more H+ ions it produces and decreases the pH of the solution

protons

the number of ___ in a solution determines how acid-base reations occur

carbon, hydrogen

all organic molecules contain ___ and ___ linked by covalent bonds

• also oxygen and nitrogen

• Nucleic acids also have phosphorus

• proteins also have sulfur

• CHONPS

Carbon

___atoms in a molecule give biological molecules its overall shape-backbone

functional groups

the behavior of a molecule is dictated by the other groups of atioms bonded to C (CHONPS)

amino functional group

positively charged, basic

• in water, attracts a H ion and becomes positively charged

• NH2

carboxyl functional group

negatively charged, acidic

• in water, releases a proton and becomes negatively charged

• COOH

phosphate functional group

charged and acidic

• in water, releases 2 protons and winds up with a negative 2 charge

• H₂PO₄

hydroxyl functional group

polar

• has hydrogen bonds

• OH

Methyl

Nonpolar

• modifies protein and cytosine nucleotide

valence electrons, stable

ability of an atom to react depends on teh total number of its ____

• when it is full the atom is___

unicellular, multicellular

protists can be ____

unicellular or multicellular

fungi can be ____