Test 1 Flashcards
Levels of Organization - Least to Most Complex
Atoms
Molecules
Cells
Tissue
Organ
Organ System
Organism
Population
Community
Ecosystem
Biosphere
Steps of Scientific Method
observe natural phenomenon
identify question/problem to explore
develop testable hypothesis
make a prediction
test the prediction
Control Group
standard to compare test group against
Variable
aspect of an object/event that may differ with the time or between subjects
Cell Theory
cells make up all living things
Germ Theory
germs are the root cause of diseases spreading and becoming infectious
Theory of Evolution
over time, changes in organisms occur
5 Fundamental Characteristics of Life
- cells - organisms are made up of membrane-bound cells
- replication - organisms are capable of reproduction
- evolution - populations of organisms are continually evolving
- information - organisms process hereditary information encoded in genes/environment
Homostasis
state of chemical and physical stability
Primary Elements Found In The Human Body
oxygen
carbon
hydrogen
nitrogen
calcium
phosphorus
potassium
sulfur
sodium
chlorine
magnesium
iron
iodine
3 Primary Subatomic Particles
protons
neutrons
electrons
Atomic Number
shares number of protons
Atomic Mass
sum of protons and neutrons
Chemical Symbol
abbreviates chemical name
Chemical Name
name of the element
Isotope
form of an atom that has the same number of protons and different number of neutrons
Radioisotope
isotopes that have radioactive elements, emits energy and particles to stabilize the nucleus of a radioisotope
Electron Valency
indicates atom will bond with others
Chemical Compound
combination of two or more different elements
proportions never vary
Chemical Mixture
two or more kinds of molecules mingle
proportions may be different
Ionic Bond
joins atoms with opposite electrical charges
Covalent Bond
atoms share two or more electrons
two atoms each have one electron in outer shell and needs one more to be complete
Non-Polar Covalent Bond
two atoms pull equally on electrons
no charge difference at the two ends
hydrophobic
Polar Covalent Bond
two atoms DO NOT pull equally on electrons
the one with the most protons pulls more and has a sightly more negative charge
hydrophilic
Hydrogen Bond
weak link formed between a covalently bonded hydrogen atom taking part in a separate covalent bond
Characteristics of Water
water molecules are polar
polar molecules are attracted to water (hydrophilic)
non-polar molecules are hydrophobic (repel by water)
Water As A Solvent
chemical reactions occur in water-based solutions, ions and polar molecules dissolve easily in it
Free Radicals
unstable missing electron in outer shell, molecule released by oxidation reactions
Antioxidants
gives up a free electron to the free radical to stabilize
pH Scale
measures the relative concentration of H+ (hydrogen) in fluids
Bicarbonate Buffer System
buffers protect against pH changes
buffers happen in biological systems and operate as a balancing system - can only bind or release H+
Nucleus Charge
the nuceli of atoms are positive
positive repels other positives, so atomic nuclei will repel each other
Electron Charge
electrons are negative, so (positive) atomic nuclei will attract (negative) electrons
Electron Shells
electrons orbit the nucleus in a shell
shell 1 can have up to 2 electrons
shell 2 and 3 can have up to 8
Chemical Reactions - Condensation
two molecules covalently bond into a larger one
Chemical Reactions - Hydrolysis
molecule splits into two smaller ones
Chemical Reactions - Transfer of Functional Groups
one molecule gives up a functional group, and a different molecule immediately accepts it
Chemical Reactions - Electron Transfer
one molecule donates electrons to another molecule
Chemical Reactions - Rearrangment
moving internal bonds converts one type of organic compound to another
Types of Molecules
enzymes speed reactions
polymer
carbohydrate
protein
lipid
nucleic acid
Types of Lipids And Their Uses
saturated and unsaturated fats
stores energy
signaling molecules
structural materials
phospholipids build cell membranes
Phospholipids
main component of cell membranes
hydrophilic head
hydrophobic tail
Nucleotides
building blocks of nucleic acids
composed of:
one sugar
at least one phosphate
one nitrogen base
Eukaryotic Cell
DNA is contained inside nucleus, membrane encloses cells and organelles
Prokaryotic Cell
nothing separates DNA from other internal cells parts
Cell Structure
outer plasma membrane
cytoplasm
DNA
Organelles in Eukaryotic Cells
outer membrane separates interior of organelle from rest of cytoplasm
membrane controls substances that enter/leave
ribosomes and centrioles lack a membrane
Nucleus
nucleus encloses DNA of a eukaryotic cell
nuclear envelope encloses the nucleus
Chromatin
cells DNA and protein associated with it, makes copy of DNA when cell is preparing to divide
Chromosome
double-stranded DNA molecule that carries genetic information
Diffusion
mechanism for moving substances across cell membrane
dissolved molecule or ion moves down their concentration gradient
passive transport - does not require energy
Osmosis
diffusion of water across a semipermerable membrane in response to solute concentration gradient
Tonicity
concentration of a solute in a solution
hypotonic fluid has fewer solutes
hypertonic fluid has more solutes
Metabolism
chemical reactions in a cell fueled by ATP, some release energy and others require it
Anabolism
metabolism that puts together small molecules
Catabolism
metabolism that breaks down large molecules
Metabolic Reactions - Reactant
any substance that takes part in a metabolic reaction
Metabolic Reactions - Intermediate
substance formed between beginning and end of metabolic pathway
Metabolic Reactions - Product
substance present at the end of a reaction or pathway
Enzymes
essential part of metabolic reactions
most enzymes are proteins
body controls activity of enzymes
ATP Via Cellular Respiration
step 1: glycolysis breaks down
occurs in cytoplasm
2 ATP produced
step 2: krebs cycle - produces energy and transports molecules
stage 2: electron transport chain
occurs inside mitochondria
