Bio principles unit one

What is life?

the condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.

What are some of the main themes of life?

Hierarchy of biological order

The cells

Heritable information

Regulation

Structure and function

Interaction with the environment

Unity and diversity

Evolution

Scientific method

What is the hierarchy of organization?

The labeling and grouping of organisms

What is the hierarchy of biological order?

Individual → organ → organ system → tissues → cells → molecules

What is an important rule of the hierarchy of biological order?

That the higher up you go the more characteristics are added

What is the cell?

The smallest unit of life

What makes a virus non-living?

There is no part of a virus with characteristics of a cell (no DNA or proteins) so it is not living

What are the only two types of cells?

Prokaryotic and eukaryotic cells

What are the two types of molecules that carry genetic material?

DNA and RNA

How to scientists identify the function of bodily structures not easily observed?

They follow a rule of biology that states that shape suggests it function. Ex: birds

What is metabolism?

sum of all chemical reactions in the body that keeps the cells alive

What is a negative feedback loop?

A molecule inhibits its own production due to an overload

What is positive feedback loop?

A molecule stimulates its own production

What is the importance of the environment in biology?

All living organisms react and respond to the environment stimulating adaptations and evolution

What molecule unifies all organisms?

DNA and RNA

What causes the diversity of life?

Slight changes between DNA bases

What is biological evolution?

gene changes in populations over many generations

What are the steps within the scientific method?

Observation → question → hypothesis → prediction → test

What is a control group?

A group that does not receive the independent variable

What is an experimental group?

A group that recieves the independent variable

What is the null hypothesis?

null means zero. so a null hypothesis states that two variables are not related.

What is matter?

Anything that takes up space and gas mass

What is mass?

The amount of matter in an object

What is weight?

The force sthat gravity exerts in the mass of an object

What is an element?

A substance that cannot be broken down into simpler substances

Where the atomic symbol come from?

The symbol comes from the first two letter of the name in either German or Latin

What 4 elements make up 96% of living matter?

Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N)

What 6 elements make of 98% of all living things?

Oxygen, carbon, hydrogen, nitrogen, sulfur, and phosphorous

What is an atom?

the smallest unit of matter that retains the properties of an element

What are the three subatomic particles?

neutrons, protons, electrons

What is the charge of a proton?

positive

What is the charge of an electron?

negative

What is the charge of a neutron?

no charge

Where are protons and neutrons located?

nucleus

Where are electrons located?

outside the nucleus in the electron cloud (orbitals)

What is the atomic number?

Number of protons in an element; every element has a unique number of protons

What is the charge of the average atom?

The charge will always be neutral unless stated otherwise

How do you calculate atomic mass?

protons + neutrons

What are isotopes?

A form of an atom that contains more neutrons and a different mass number

What can isotopes be used for?

in science: carbon dating, tracers and medicine: radiation

What are radioactive isotopes?

Atoms that release radioactive energy when they decay

What is a half life?

Length if time for an element to decay half of its radioactive neutrons

What type of atomic model do we use?

The Bohr model

What are the energy levels talked about in class

1s, 2s, 2px, 2py, 2pz

What are the characteristics of the first electron energy level?

It is the lowest energy level with the high amounts of potential energy

It holds 2 electrons max

What are characteristic of the second energy level?

It has 4 orbitals

Can fit 2 electrons per obital so 8 electrons in total

What are characteristics of the third energy levels?

Holds 8 electrons

What is an orbital?

Areas where the electron is found 90% of the time

What does s orbital mean?

It refers to a spherical orbital

What is an important characteristic of electrons in an orbital?

They are paired

How do you distribute electrons on an orbital

You start with the first group, 1s. There you place 2 elections. You then move to the 2s orbital where you do the same thing. For the 2px, 2py, and 2pz orbitals you have to evenly distribute an electron in each until 2 electrons are in each orbital

How do you write a distributed element

You write the the orbital number (1 or 2) and then you write the number of electrons that is filled in it. The number of elections must be equal to the numbers placed next to the electrons

Ex: Carbon - 1s2, 2s2, 2px1, 2py1

What is a valance shell?

outermost electron shell

What are valence electrons

Outer electrons for sharing and merging to form molecules and complex compounds

What are noble gases?

Elements whose electron shells are full so they cannot combine with other molecules

What is a property of carbon that makes it essential to life?

It's 4 valance electrons allows it to bind with many other types of elements

What is the valence of an atom?

The amount of electrons the atom needs to fill its outer shell to its capacity

What creates differences in chemical behavior between elements

Chemical behavior of an atom is based on the distribution of electrons in its shell

Why do elements bond together?

They bond to balance charges, to pair elections in their valance shells, or to fill the valance shell to its capacity

What are the 4 types of chemical bonds?

ionic, covalent, hydrogen, and van der waals forces

What are the four bonds ordered by their strength (for this class)?

1. Covalent bonds

2. Ionic bonds

3. Hydrogen bonds

4. Van de waal forces

What are ionic bonds?

It is when two atoms transfer electrons. During this process one becomes positive and the other become negative, these negative charges are attracted to each other forming ionic bonds

What is an example an ionic bondb

The bond between sodium (Na) and Chloride (Cl)

What are covalent bonds?

The aheing of electrons between atoms

What does - mean in chemistry?

It represents a single covalent bond

What does = mean in chemistry?

A double covalent bond

What is electronegativity?

Attraction an atom has to the electrons in a covalent bond. !n a covalent bond the more electronegative the atom the greater the attraction

How does valance and electronegativity interact?

Lower valance = more electronegativity

How do polar covalent bonds occur?

When atoms with different electronegativities interact with each other

What is polarity?

Difference in charges between molecules

What are hydrogen bonds?

A bond between two polar molecules with slightly different charges; a weaker form of an ionic bond

Give an example of a hydrogen bond

Ammonia and water, positive hydrogen form a slight attraction to the negative nitrogen

How does hydrogean bonds impact water density?

Because of the hydrogen bonds between the water molecules the water forms a hexagonal pattern when freezing allowing air to get between the gaps decreasing the density of the ice

Why are hydrogen bonds so important?

Dna and proteins are held together using them

What are Van der Waals forces?

Interactions of electron clouds

How are Van der Waal's forces formed?

Electrons move to one side causing a temporary change in the atoms charge making one side slightly negative and the other slightly positive. This allows atoms to temporarly bond

How can Van der Waal's forces be split?

By changes in electron movements

In a solvent what type of bond is the strongest?

Covalent bonds

What is oxidation?

The losing of electrons

What is reduction?

The receiving of an electron from another atom

What are redox reactions?

Oxidation-reduction reactions. Electrons are transferred from one molecule to another

What are molecules?

two or more atoms bonded together through COVALENT BONDS

What are some examples of molecules?

H2, O2, or H2O

What are compounds?

A substance consisting of two or more elements in a fixed ratio