BIO 103- Exam 1 Flashcards
science
a systematic process for learning about the world and testing our understanding of it
The accumulated body of knowledge arising from the dynamic process of observation, testing, and discovery
fact
an observation of a phenomenon in nature (ex: leaves of plants are green)
hypothesis
an educated guess about the reason for the phenomenon (ex: the leaves reflect green light more than other wavelengths)
law
A general hypothesis or statement about the relationship of natural quantities that has been tested over and over again and has not been contradicted. (ex: relationship between chlorophyll and the color of leaves)
theory
a comprehensive explanation of some aspects of nature that is supported by a vast body of evidence and that generated testable and falsifiable predictions. NOT a vague or untested idea
the scientific method
the process of systematically testing hypotheses to explain natural phenomena
the process of the scientific method
- a scientist makes an observation and asked questions
- scientist will create a hypothesis (must be testable)
- the hypothesis generated predictions which can be tested
- the results will either support or reject the hypothesis
hypothesis testing
- break down the hypothesis statement into cause and effect
- design an experiment to specifically test whether changing the CAUSE produces different EFFECTS
independent variable
the “cause” variable ( we manipulate or change it)
dependent variable
the “effect” variable (response that is measured when independent variable changes)
control
the zero level of the independent variable, serves as the baseline or default level
replication
number of samples within each level of independent variable
controlled experiment
keep constant all other variables that could affect the response (controlled variables or constants)
organism
a living being
shared characteristics of life
- energy and matter
- cells
- information stored in the form of DNA
-environmental information
-replication/reproduction
-populations evolve
-product of evolution
energy and matter
all living things use and acquire matter. During this process, all living things release energy into the environment
all things are made up of cells
cells are organized compartments made of a plasma membrane, cytoplasm, and DNA. they reproduce by replicating themselves and come in all different shapes, sizes, and functions
information stored in form of DNA
DNA is made of nucleic aids which are information carrying biomolecules. Each DNA molecule is divided into genes which code for proteins.
DNA is coped onto mRNA. Ribosomes then read the information on the mRNA and create proteins
what does DNA stand for?
deoxyribonucleic acid
what does RNA stand for?
ribonucleic acid
environment information
organisms process information from their environment
cells take in information, which leads to cellular signaling and a response to stimulus
replication/reproduction
All organisms are capable of reproduction
For life on Earth to continue to exist, cells must replicate
populations of living organisms evolve
change in heritable characteristics over generations within a population (evolution)
product of evolution
all living things are the product of evolution
all living things bear these similarities (shared characteristics of lfie) as a result of evolution
are viruses living organisms?
they are not living organisms
matter
anything that has mass and occupies space
atom
the unit of matter
nucleus of an atom
contains neutrons (no charge) and protons (positive charge)
electrons
negative charge, surround the nucleus
what is the relationship between protons and electrons?
the number of electrons equals the number of protons. different elements mean different number of electrons and protons
molecule
two or more atoms joined by bonds
the law of conservation of matter
states that in physical or chemical changes, matter is neither created nor destroyed. atoms and molecules are simply rearranged
chemistry of life-carbon
- life on earth is carbon based
- carbon atoms are small and stable (unstable atoms lose protons and electrons)
-carbon bonds are stable in water solutions (cytoplasm is water based)
-carbon atoms can form multiple chemical bonds - carbon-carbon links form the backbone of biological molecules with other atoms attached
chemistry of life-water
- water is critical to life on earth
-excellent solvent (cytoplasm holds many salts)
-high boiling and low freezing points (life forms live well within this range) - high heat capacity (changes temperature slowly)
- high cohesion and adhesion
cohesion
molecules of same substance stick together, makes water molecules stick to each other and pull up against gravity
adhesion
molecules of different substances stick together, makes water molecules stick to tubes inside plants and get pulled up
polymers
large molecules made of monomers
monomers
building block molecules
carbohydrates
- monomers are monosaccharides (simple sugars, glucose, fructose, galactose)
- source of fast energy for the cell: fuel
-carbohydrates stored in cells for future use: break down later as glucose source
disachharides
Two Monosaccharides bonded together
Common Disaccharides
Lactose - galactose and glucose
Maltose - glucose and glucose
Sucrose - fructose and glucose
starches
complex sugars, polymers made up of several monomers
lipids
- monomers are glycerol and fatty acid chains
- saturated fats: fatty acids have only single bonds between C atoms
- unsaturated fats: fatty acids have double and triple bonds between C atoms
- fuel for cell: long term energy storage
- contributes to cell structure: phospholipids (protective later)
-transport nutrients and related to cholesterol
proteins
- monomer is amino acids (20 different amino acids)
-difference between amino acids: R side chain comprises of C,H and other atoms - needed for structure, metabolic enzymes, transport, cell signaling, movement, gene expression, channels and pumps, and protection
-amino acid chains get folded into a shape that is important for the protein function
nucleic acid
- monomer is nucleotides
- nucleotides are made up of phosphate group, ribose sugar (RNA), deoxyribose sugar (DNA), and a nitrogenous base (A, G, C, T (only in DNA), and U( only in RNA)
- the sequence of nucleotides is used for making proteins
-DNA: primary genetic material for all living things - RNA: carries information from DNA to ribosomes
diversity of molecules
- different monomers can be made using the same basic molecule and changing one section
- a diversity of polymers can be made by connecting monomers in different ways
- small molecular changes around a basic structure can yield large differences
what has to be inside a cell?
DNA, RNA, ribosomes, proteins, amino acids, and nucleotides
ribosomes
made up of proteins and RNA, ribosomes read messages on mRNA and make proteins
prokaryotic cell structure
- contains plasma membrane and phospholipid bilayer
- contain a cell wall outside plasma membrane
-no nucleus
-DNA is free floating in the cytoplasm - contains plasmid ( small circular piece of DNA, separate from chromosomes)
-no organelles
-rotating flagellum and cilia - few or no internal membranes
-bacteria and archea
eukaryotic cell structure
- fungi, animals, plants, protists
-nucleus, endoplasmic reticulum, golgi apparatus, lysosomes, mitochondria, chloroplasts, and central vacuole
plasma membrane
-A selectively-permeable phospholipid bilayer forming the boundary of the cells
- compounds in the plasma membrane include phospholipids, cholesterol, proteins, and carbohydrates
- fluid mosaic: not rigid, flexible and able to move, combination of many compounds
diffusion
molecules move from area of high concentration to area of low concentration of the molecule
osmosis
water moves from an area of higher water concentration to area of lower water concentration across a semi-permeable membrane
hypertonic
higher salt concentration than reference solution, lower water concentration (cells shrivel)
hypotonic
lower salt concentrations than reference solution, higher water concentration (cells burst)
isotonic
same concentration of salts as reference solution, cells maintain shape
nuclear envelope
phospholipid bilayer
chromatin: all the chromosomes within the nucleus
function: packages DNA, ribosomal synthesis
endoplasmic reticulum
series of interconnected membranes, function: transport lipids and proteins
lysosomes
animal cells only, destroys waste and disease agents, contains digestive enzymes
mitochondria
generates ATP, the primary source of energy in the cell
endosymbiosis theory
A theory that mitochondria and chloroplasts originated from bacteria that took up residence within a primordial eukaryotic cell.
chloroplast origin
thought to have originated when a eukaryote engulfed a cyanobacterium.
chloroplast
plant cells only, contains chlorophyll (green pigment), chlorophyll traps light energy and converts inorganic carbon into glucose
cell theory
all organisms are made of cells (one or more) and all cells come from other cells
all single-celled organisms in a population are related by common ancestry and all cells in a multicellular organism are connected by common ancestry
