Biology - Unit 1: High School

Biology

The study of living things

Observation

Noticing and describing events in an orderly way

Hypothesis

A scientific explanation that can be tested through experimentation or observation

Controlled Experiment

An experiment in which only one variable is changed

Independent Variable

The variable that is deliberately changed in an experiment

Dependent variable

The variable this is observed and changes in response to the independent variable

Control Group

Baseline group that does not have changes in the independent variable

Scientific Theory

A well-tested and widely accepted explanation for a phenomenon

Research Bias

Process during which the researcher influences the results, either knowingly or unknowingly

Placebo

A substance that has no therapeutic effect, often used as a control in experiments (if there are two groups, one who gets a pill, and one who doesn't, both will get something. But only one will be a real pill that does stuff. The other will be a placebo. To make sure there is no psychological effect, like you feel better because you THINK a pill works, but it doesn't, the placebo effect. This eliminates that by giving both groups pills, but one is fake, aka a placebo).

Double-blind study

Study in which neither the participants nor the researchers know who is receiving a particular treatment

Properties of Life

1. Organization

2. Metabolism

3. Homeostasis

4. Growth

5.Reproduction

6. Response

7. Evolution

Organization (property of life)

Living things are highly organized (meaning they contain specialized, coordinated parts) and are made up of one or more cells.

Metabolism (property of life)

Living things use energy and consume nutrients to carry the chemical reactions that sustain life. The sum of all biochemical reactions in an organism (which are necessary for life) is the metabolism.

Homeostasis (property of life)

Living organisms control their internal environment to maintain the relatively narrow range of conditions needed for cell function

Growth (property of life)

Living organisms grow, individual cells become larger in size, and multi cellular organisms accumulate many cells through cell division

Reproduction (property of life)

Living organisms can reproduce themselves to create new organisms.

Response (property of life)

Living organisms respond to stimuli or changes in their environment.

Evolution (property of life)

The genetic makeup of a population may change over time. The desirable qualities are kept, and the not so good ones are weeded out. This is adaptability. Natural selection also comes into play with evolution.

Scientific Method

The scientific method involves making observations and asking questions. It can be a continuous cycle.

Scientific Method Steps

1. Observation (make an observation)

2. Question (ask a question. Why?)

3. Hypothesis (must be testable)

4. Prediction (make a prediction)

5. Test prediction (through observation or experimentation)

6. Refinement and Iteration (redo the test with your new knowledge. Ask more questions)

How to avoid research bias

1. Having a large sample size in the experiment

2. Including ALL data points (all data is needed, whether is supports your hypotheses or not)

3. Using placebos when appropriate (the test subject doesn't know if the medicine is real or not. This lets researches observe the effects it has on the person)

4. Implementing double-bind studies (eliminates observer bias)

5. Repeat trials (to increase accuracy of results and reduce errors and mistakes)

Biological Macromolecule

A large, organic molecule such as carbohydrates, lipids, proteins, and nucleic acids

Monomer

A molecule that is a building block for larger molecules (polymers). I.E: An amino acid acts as the building blocks for proteins.

Polymer

A large molecule made of repeating subunits (monomers). I.E: a carbohydrate is a polymer that is made of repeating monosaccharides.

Carbohydrates (building blocks, functions, and examples)

Building Blocks- Monosaccharides (simple sugars)

Functions- Provide cells with quick/short-term energy, source of dietary fiber

Example- Glucose, sucrose, starch, cellulose, chitin

Lipids (building blocks, functions, examples)

B.B- Fatty Acids and glycerol

Functions- Provide cells with long-term energy, make up biological membranes

Example- Fats, phospholipids, waxes, oils, grease, steroids

Proteins (functions, building blocks, and examples)

B.B- Amino Acids

Function- Provide cell structure, send chemical signals, speed up chemical reactions, etc

Example- Keratin (found in hair and nails), hormones, enzymes, antibodies

Nucleic Acids (building blocks, functions, examples)

Building Blocks: Nucleotides

Functions: Store and pass on genetic information

Examples: DNA and RNA

10 essential amino acids

arginine

histadine

leucine

isoleucine

lysine

threonine

methionine

phenylalanine

tryptophan

valine

Polar Molecule

A neutral molecule that has an unequal internal distribution of charge, leading to partially positive and negative regions

Cohesion

Cohesion is the attraction of molecules for other molecules of the same kind

Adhesion

Adhesion is the attraction of molecules for other molecules of the different kind

Density

The mass per unit volume of a substance

Specific Heat Capacity

The amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius

Heat of Vaporization

The amount of energy needed to change one gram of a liquid substance to a gas at constant temperature

Water Molecule formula (include the delta)

O δ-

/ \

H δ+ H δ+

Is water polar?

Yes.

Water molecules are polar, with partial positive charges on the hydrogens, a partial negative charge on the oxygen, and a bent overall structure.

Is water a solvent?

Yes, an excellent solvent. Water has the unique ability to dissolve many polar and ionic substances.

What type of heat capacity does water have?

Water has high heat capacity. It takes a lot of energy to raise the temperature of a certain amount of water by a degree, so water helps with regulating temperature in the environment.

Water properties

- Water has cohesive and adhesive properties.

- Water molecules have strong cohesive forces due to their ability to form hydrogen bonds with one another.

- Water also has adhesive properties that allow it to stick to substances other than itself.

Is water more or less dense as a solid then as a liquid?

Water is less dense as a solid than as a liquid. As water freezes, the molecules form a crystalline structure that spaces the molecules further apart than in liquid water.

This property is important, it keeps ponds, lakes, and oceans from freezing solid and allows life to continue to thrive under the icy surface.

pH

The measure of the hydrogen ion (H+) concentration in a solution

Acid

Solution with a higher concentration of hydrogen ions than pure water

Base

Solution with a lower concentration of hydrogen ions than pure water

What does a pH scale do?

The pH scale is used to rank solutions in terms of how acidic or how basic they are

What is a neutral pH

7

What is an acidic pH

anything below 7

What is a basic pH

anything above 7

pH of bleach

12.6

pH of baking soda

9

pH of blood

7.3

pH of lemon juice

2

What is a strong base

A higher pH number

What is a strong acid

A lower pH number

Cell

The smallest living unit of life

What are the functions of carbohydrates.

Carbohydrates provide cells with quick/short-term energy, source of dietary fiber.

What are some examples of carbohydrates?

Examples are glucose, sucrose, starch, cellulose, chitin

What are the building blocks of lipids?

Fatty acids and glycerol

What are some functions of lipids?

Provide cells with long-term energy, make up biological membranes

What are some examples of lipids?

Fats, phospholipids, waxes, oils, grease, steroids

What are the building blocks of proteins?

Amino acids

What are some functions of proteins?

Provide cell structure, send chemical signals, speed up chemical reactions, etc

What are some examples of proteins?

Keratin (found in hair and nails), hormones, enzymes, antibodies

What are the building blocks of nucleic acids?

Nucleotides

What are some functions of nucleic acids?

Store and pass on genetic information

What are two examples of nucleic acids?

DNA, RNA

Common Misconception: Macromolecules are described as big, but they are just made of a lot of tiny atoms. They are still microscopic.

This is a statement

What are lipids

Lipids are a class of molecules that are not so water soluble

Define hydrophobic

Not attracted to water

Define hydrophilic

Attracted to water

True or False: Some parts of lipids are hydrophilic, and some parts are hydrophobic

True

What are some functions of lipids?

Store energy, signal, act as memrbanes

Why are lipids not soluble in water?

Water soluble substances are polar molecules usually. Hydrocarbon chains in lipids aren't polar, so not as soluble in water

What makes a fat saturated?

If carbons are bonded to as many hydrogens as possible, then it is a saturated fat (saturated with hydrogens. Saturated means "soaked in")

What makes a fat unsaturated?

If in theory carbon could bond with more hydrogen, then a fat is unsaturated. There are one or more double bonds, which causes the carbons not to bond with every possible hydrogen atom.

Are many vitamins lipids? Why do they need fats?

Many vitamins are not as soluble in water (and hence are lipids) and they need fats to absorb into the body

All lipids have long chains of ___ that are not so soluble in water

Hydrocarbon

What does DNA do?

Stores hereditary material

What is a chromosome?

A really long string of DNA molecules

Are nucleic acids polymers or monomers?

Nucleic acids are polymers

What are the building blocks of nucleic acids? Are they monomers or polymers?

The building blocks of nucleic acids are nucleotides. They are monomers.

True or False: There are different types of nucleotides. What are the different kinds?

True. There are adenine and thymine (which go together) and guanine and cytosine (which go together).

Your body needs some things it cannot produce. These are vitamins and minerals.

This is just a statement

Define organic

Compounds with carbons

Are vitamins organic or not?

Vitamins are organic

Are minerals organic or not?

Minerals are not organic

Give some examples of vitamins that are fat soluble (able to dissolve in fat)

Vitamins A, D, E, and K

Which are easier to overdose on, fat or water soluble vitamins?

Fat soluble vitamins. This is because water soluble vitamins are easy to flush out of your system, because they dissolve in water. But fat soluble vitamins are harder to get out of your system, so they are easier to overdose on.

Give an example of vitamins that are water soluble

Vitamin C

Why are carrots good for the eyes?

They have betacarotene, which your body will turn into Vitamin A (for eyes) when it is eaten

What are oranges good for? Which vitamin do they mainly have?

They are good for the immune system. They mainly have Vitamin C

Name typical minerals and their uses

Some minerals are:

- Phosphorus (useful in DNA, RNA, and ATP)

- Calcium (good for bones and muscle contraction)

- Potassium (sends signals down neurons)

- Magnesium (helps with muscle contraction)

- Iron (transports oxygen in the blood)

Can foods have both vitamins and minerals?

Yes

What kind of bonding does water have?

Covalent bonds

What does covalent bonds mean?

Each element that is bonded has a pair of electrons that they share.

Oxygen is electromangetic. What does this mean? (specifically in the case of water)

The oxygen tries to keep the electrons for itself, so it has them way more often than the hydrogen does.

What happens as a result of oxygen's electromagnetism in water?

The side without the hydrogen is slightly negative, and the side with the hydrogen is slight positive.

What is the symbol for slightly charged?

Delta. Delta + is slightly positive, and delta - is slightly negative. (see photo).

What is a hydrogen bond?

In a molecule, the partial negative section is attracted to the partially positive section.