BIO 101 - UNIT 1

Steps of the Scientific Method

observation, question, research, hypothesis, experiment, results, conclusion

Hypothesis

Tested with 1 experiment, subject to immediate testing, narrow in scope

Theory

Many different trends, broad in scope, already supported by large body of evidence

Control group

In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.

control experiment

an experiment designed to control for variables affecting the results of another experiment

confounding variables

variables not controlled between 2 groups in a study

blind experiment

An experiment in which the subjects do not know whether they are members of the experimental group or the control group.

independent variable

variable that is manipulated

dependent variable

a variable (often denoted by y ) whose value depends on that of another.

Pseudoscience

A fake or false science that makes claims based on little or no scientific evidence.

anecdotal evidence

an informal observation that has not been systematically tested

Characteristics of living things

order, energy and matter processing, reproduction, growth and development, response to the environment, evolutionary adaptations

biosphere

consists of all life on Earth

ecosystem

consists of the living and nonliving components

community

consists of all the interacting populations in an ecosystem

population

a group of interacting individuals of one species

organism

an individual living being

organ system

group of organs that work together

organ

consists of multiple tissues that cooperate to perform a specific task

tissue

an integrated group of similar cells that work together

cell

fundamental unit of life

organelle

a component of the cell that performs a specific function

molecule

A group of atoms bonded together

atom

fundamental unit of matter

Shape determines \______________

Function

atom + atom \=

molecule

Element

basic substance that can't be broken down

What 4 elements make up the bulk of living cells?

oxygen, carbon, hydrogen, nitrogen

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions.

Protons

have positive charge, located in nucleus, number of protons determines the chemical element

Neutrons

have no charge, located in nucleus, number of neutrons determines the isotope

Electrons

negative charge, orbit nucleus at high speed, little mass, number of electrons determines an atom's ion state and chemical reactivity

Ion

A charged atom

What creates a positive charge?

More protons than electrons due to a loss of electrons.

What creates a negative charge?

More electrons than protons due to a gain of electrons.

Hydrogen bond

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

polar

describes a molecule in which the positive and negative charges are separated

non-polar

a molecule in which all atoms have the same electronegativity and the electron distribution is equal

What kind of molecule is water?

polar, because the bonds between the hydrogen and oxygen molecules are always at a 45 degree angle, ALSO oxygen has a greater pull than hydrogen, making the oxygen negatively charged and the hydrogen positively charged

Acids

pH less than 7

Bases

pH greater than 7

Buffers

weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH

The lower the pH of a solution, the \______.

more H+ ions in a solution

each number on the pH scale

represents a 10 fold difference in H+ ion concentration

The higher the pH of a solution, the \__________.

more OH- ions in a solution

4 unique properties of water

neutral solution, all water molecules connect to other water molecules

SALT

SUCKS

monomers

small unit that can join together with other small units to form polymers (ONE)

polymers

molecules composed of many monomers; makes up macromolecules (MANY)

Carbohydrates are composed of what atoms?

carbon, hydrogen, oxygen

Saccharides

carbohydrate units, sugar

Monosaccharides

glucose, fructose, galactose

Disaccharides

sucrose, maltose, lactose

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides

Proteins

Chains of amino acids (meat/meat substitutes)

Carbohydrates

the starches and sugars present in foods (sugars)

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes (butter)

Triglycerides

lipid molecule, glycerol head, 3 fatty acid tails

Glycerol head

hydrophilic

fatty acid tails

hydrophobic

Steroids

carbon skeleton consisting of four fused rings, carbohydrate, ex. cholesterol

Saturated fats

fats that are solid at room temperature, can compact, HAS STRAIGHT TAILS, no double bonds,

Unsaturated fats

liquid at room temperature, can't compact, HAS BENT TAILS, double bonds

Why are trans fats bad?

science took plant fats and made them solid like animal fat, except trans fats don't spoil like animal fat, and it makes the shape of the tails different, which our body can notice and can't process!

Enzymes

Proteins that speed up chemical reactions, think: PACMAN eating bonds

Metabolism

the sum of all chemical processes that occur in an organism

-ase

enzyme

-ose

sugar

Substrate

The reactant on which an enzyme works.

Prokaryotic

An organism whose cells do not have an enclosed nucleus, such as bacteria.

Eukaryotic

Cell with a nucleus (surrounded by its own membrane) and other internal organelles. Plants and animals.

Unique to plant cells

cell wall, chloroplasts, central vacuole

Unique to animal cells

lysosomes

phospholipid bilayer

Plasma membrane layers composed of phospholipid molecules arranged with polar heads facing the outside and nonpolar tails facing the inside.

cystic fibrosis

genetic disorder where the transport proteins are misshapen, which causes super thick mucus build up in lungs

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Flagella

whiplike tails found in one-celled organisms to aid in movement

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Rough ER

That portion of the endoplasmic reticulum studded with ribosomes. Folds the amino acid chain so it can have a different function

Smooth ER

Makes lipids

Receptor proteins

receives chemical signals from outside the cell

Transport proteins

allow passage of hydrophilic substances across the membrane

Recognition proteins

provide a "fingerprint" for the cell, so it can be recognized by other cells

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Ribosomes

site of protein synthesis

Vesicles

small membrane sacs that specialize in moving products into, out of, and within a cell

Chloroplasts

organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Central vacuole

A large vacuole that rests at the center of most plant cells and is filled with a solution that contains a high concentration of solutes.

Cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water through a selectively permeable membrane

hypotonic

solution with lower solute concentration than the cell

isotonic

when the concentration of two solutions is the same

hypertonic

solution with higher solute concentration than the cell

cellular respiration

the process by which cells use oxygen to produce energy from food

cellular respiration equation

C6H12O6 + 6O2 --\> 6CO2 + 6H2O + ATP

Photosynthesis

Conversion of light energy from the sun into chemical energy.

Photosynthesis equation

6CO2 + 6H2O \------\> C6H12O6 + 6O2