Chapter 1- the Nature of Life

Biology

Chapter 1- The Nature of Life

The goal of science is to investigate and understand nature, to explain events in nature, and to use those explanations to make useful predictions.
Science is an organized way of using evidence to learn about the natural world.
Observation involves using 1 or more of the senses to gather info
Data is info gathered from observations called evidence/data.
How do you interpret the evidence?
Inference is a logical interpretation based on prior knowledge and experience.
How do you explain the evidence?
Hypothesis is a possible explanation for a set of observations or an answer to a scientific question.

How to design an experiment?
Hypothesis
Set up a controlled experiment
Change the variable in your test (only 1 variable)
Record/Analyze the results from the experiment
Draw a conclusion

Whenever possible, a hypothesis should be tested by an experiment in which 1 variable is changed at a time. All other variables should be kept unchanged, or controlled
Spontaneous generation is a hypothesis (disproved) stating that life could arise from nonliving matter
Manipulated variable (Independent Variable [IV]) is a factor in a experiment that a scientist purposely changes
Responding Variable (Dependent Variable [DV]) is a factor in a experiment that scientist wants to observe. Which may change in response to the IV
What do you do when experiments are not possible?
Try an alternate investigation. It is not always possible to test a hypothesis.
Theory is a well-tested explanation that unifies a broad range of observation.
Biology is the science that seeks to understand the living world
What are characteristics of Living Things?
Living things are made up of units called cells
Living things reproduce
Living things are based on a universal genetic code
Living things grow and develop
Living things obtain and use materials and energy
Living things respond to their environment
Living things maintain a stable internal environment
Taken as a group, living things change over time.
A cell is a collection of living matter enclosed by a barrier that separates the cell from its surroundings
Sexual reproduction is 2 cells from different parents unite to produce the first cell of the new organism.
Asexual reproduction the new organism has a single parent
Metabolism is a set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life process.
Homeostasis is the process by which organisms keep their internal conditions relatively stable.
To Evolve is to change over time
What are the braches of Biology?
The Many Levels at which life can be studied include molecules, cells, organisms, populations of a single organism, communities of populations living in the same area, and the biosphere.
What is a common measurement system?
Metric system is a decimal system of measurement whose units is based on a certain physical standards and is scaled on multiples of 10.
How do you analyze biological data?
Record the data in a table and then make a graph.
Microscopes are devices that produce magnified images of structures that are too small to see with the unaided eye
Compound Light Microscopes allow light to pass through the specimen and use 2 lenses on image
Electron Microscopes focus beams of electrons on specimens to form an image
What are 2 lab techniques?
Cell structures
Cell Fractionation
Cell culture is a group of cell growth in a nutrient solution from a single original cell
Cell fractionation is a technique in which cells are broken into pieces and the different cell parts are separated.

Chapter 2- The Chemistry of Life

An Atom is the basic unit of matter. Includes parts such as a nucleus: protons, electrons, and neutrons.
A nucleus is the center of a atom in which holds protons & neutrons.
Electrons are a negatively charged particle (-) with 1/1840 the mass pf a proton. Always in motion surrounding the nucleus but remain outside.
What property do elements & isotopes have?
Because they have the same number of electrons & protons, all isotopes of an element have the same chemical properties.
An element is asubstance consisting entirely of one type of atom
An isotope is an atom of an element that has a number of neutrons different from that of other atoms of the same element.
What are the main types of chemical bonds?
Ionic bond which is a bond formed when 1 or more electrons are transferred from one atom to another
Covalent bond which is abond formed by the sharing of electrons between 2 atoms
A molecule is the smallest unit of most compounds
Van der Waals Forces are a slight attraction that develops between the oppositely charges regions of nearby molecules
What is a Water Molecule?
H20 is neutral (10 protons and 10 electrons). The oxygen atom has a much stronger attraction than the hydrogen atom. The charges are uneven which is called a Polar molecule. A water molecule is polar because there is an uneven distribution between the oxygen and the hydrogen atoms.
Cohesion is an attraction between molecules of the same substance.
Adhesion is an attraction between molecules of different substances
Solutions are a mixture 2 or more substances in which the molecules of the substances are evenly distributed.
Solute is a substance that is dissolved in a solvent to make a solution
Solvent is a substance in which a solute is dissolved to form a solution
Suspensions are mixtures of water and nondissolved materials
pH Scale is a measurement system used to indicate the concentrations of hydrogen ions (H+) in solutions; ranges from 0 to 14
An Acid is a compound that forms hydrogen ions (H+) in solutions. On pH Scale 0-6
A base is a compound that produces hydroxide ions (OH-ions) in solutions. On pH Scale 7-14
Buffers are weak acids or bases that can react with strong acids or bases to help prevent sharp, sudden changes in pH.
Monomers are small units that can join together with other small units to from polymers
Polymers are large compounds from combinations of many monomers
What are Carbohydrates?
Carbohydrates are compounds made up of carbon, hydrogen, and oxygen atoms
Monosaccharides are a single sugar molecule. They are the monomer of the Carbohydrates.
Polysaccharides are a large macromolecule formed from monosaccharides. They are the polymers of the Carbohydrates.
What are Lipids?
Lipids are macromolecules made mainly from carbon and hydrogen atoms; include fats, oils, and waxes
Nucleic Acids are macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus. They store hereditary or genetic info. There are 2 kinds; ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).
Nucleotide is a monomer of nucleic acids made up of a –5-carbon sugar, a phosphate group, and a nitrogenous base.
Protein is a macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and to make up enzymes. * Some proteins control the rate of reactions and regulate cell processes. Some are used for bone and muscles. Others transport substances into or out of the cell or help fight disease.
Amino Acids are compounds with an amino group (-NH2) on one end and a carboxyl group (-COOH)
What do chemical reactions involve?
They involve the breaking down of bonds in reactants and the formation of new bonds in products.
Chemical Reactions are processes that change 1 set of chemicals into another set of chemicals.
Reactants are elements or compounds that enters into a chemical reaction
Products are the elements or compounds produced by a chemical reaction.
EXAMPLE OF CHEMICAL REACTION:
CO2 + H2O H2CO3

H2CO3 CO2 + H2O

What are enzymes?
Enzymes are proteins that act as biological catalysts.
Catalysts are substances that speed up chemical reactions that take place in the cells.
Substrates are the reactant of an enzyme-catalyzed reaction.

Common Metric Units

LENGTHMASS

1 meter (m) = 100 centimeters (cm)1 kilogram (kg) = 1000 grams (g)

1 meter = 1000 millimeters (mm)1 gram = 1000 milligrams (mg)

1000 meters = 1 kilometer (km)1000 kilograms = 1 metric ton (t)

VOLUMETEMPERATURE

1 liter (L) = 1000 milliliters (mL)0°C= freezing point of water

1 liter = 1000 cubic centimeters (cm3)100°C= boiling point of water

Chapter 7-Cells

What is “Cell theory”?
All living things are composed of cells
Cells are the basic units of structure & function in living things
New cells are produced from existing cells
A cell is a collection of living matter enclosed by a barrier the separates the cell from its surroundings; basic unit of all forms of life.
What are the basic cell structures?
Cell membrane
Cell Wall
Cell membrane is a thin, flexible barrier around a cell; regulates what enters and exits the cell
Cell wall is a strong layer around the cell membrane in plants
A nucleus is a small, dense region within most nuclei in which the assembly of ribosome begins
Cytoplasm is the material inside the cell membrane—but not including the nucleus
Prokaryotes are singe-celled micro organisms that lacks of a nucleus
Eukaryotes are organisms whose cells contain nuclei
An organelle is a specialized structure that performs important cellular functions within the eukaryotic cell
What is the main function of the cell wall?
Is to provide support and protection for the cell
What does the nucleus control?
It controls the cell processes and contains the hereditary info of the DNA
The granular material visible within the nucleus is call chromatin. It’s consisting of DNA bound to protein.
When a cell divides, chromatin condenses to form chromosomes. These are distinct, threadlike structures containing the genetic info that is passed from 1 generation to the next.
Most nuclei also contain a small, dense region known as nucleolus. The function is to begin the assembly of ribosomes
A double-membrane layer called the nuclear envelope surrounds the nucleus. It allows material to move into and out of the nucleus.
The cytoskeleton helps to support the cell. It is a network of protein filaments that helps the cell maintain its shape. It is also involved in many forms of cell movement.
Microtubules are hollow tubes of protein. They are within the cytoskeleton.
Microfilaments are long, thin fibers that function in the movement and support of the cell.
Proteins are assembled on ribosomes. They are small particles made of RNA and protein. They produce protein following coded instructions that from the nucleus.
Eukaryotic cells also contain an internal membrane system known as the endoplasmic reticulum, or ER. The endoplasmic reticulum is the organelle in which components of the cell membrane are assembled and some proteins are modified.
Proteins produced by the rough endoplasmic reticulum move into a stack of membranes called the Golgi apparatus. Enzymes in the GA attach carbohydrates and lipids to proteins.
Lysosomes are small organelles filled with enzymes. 1 function is to break down lipids, carbohydrates, and proteins from food into particles that can be used by the rest of the cell.
Cells often store materials such as water, salts, proteins, and carbohydrates in saclike structures known as vacuoles.
The chloroplasts are found in plants and some other organisms. Chloroplasts use energy from the sunlight to make energy-rich food molecules in a process known as photosynthesis.
The mitochondria are organelles that release energy from stored food molecules. Mitochondria use energy from food to make high-energy compounds that the cell can use to power growth, development, and movement.
The core of nearly all cell membranes is a double-layered sheet called a liquid bilayer. It gives the cell membrane a tough, flexible structure that forms a strong barrier between the cell and its surroundings.
Diffusion is the process by which molecules move from an area where they are more concentration to an area of lower concentration.
Concentration the mass of solute in a given volume of solution, or mass/volume
Selectively permeable is when membranes only allow certain substances to pass through
Osmosis is the diffusion of water through the selectively permeable membrane
Facilitated diffusion is the movement of specific molecules across cellmembranes through protein channels
Active transport is a energy-requiring process that moves material across a cell membrane against a concentration difference
Endocytosis is a process by which a cell takes material into the cell by enfolding of the cell membrane
Phagocytosis is a process by which extensions of cytoplasm surround & engulf large particles & take them into the cell
Exocytosis is a process by which a cell releases large amounts of material
Multicellular organisms have cell specialization, or separate roles for each type of cell. Cells in multicellular organisms are specialized to perform particular functions with the organisms.
What are the levels of organization in multicellular organisms?
Individual cells, tissues, organs, and organ systems
Tissue is a group similar to cells that perform a particular function
Organs are a group of tissues that work together to perform closely related functions
Organ system is a group of organs that work together to perform a specific function

Chapter 8- Photosynthesis

Where do plants get the energy they need to produce food?
Form light from the sun
Autotrophs are organisms that can capture energy and make food from sunlight.
Heterotrophs are organisms that cannot produce their own food so they consume it from other organisms
Adenosine triphosphate (ATP) is one of the principal chemical compounds that living things use to store energy.
What is the equation for photosynthesis?
6CO2 + 6H2O C6H1206 + 6O2
Carbon dioxide + water which light makes glucose + oxygen
What does photosynthesis require?

H2O
Carbon
Light
Chlorophyll

Chlorophyll is a principal pigment of plants and other photosynthetic organisms; captures light energy.
Pigments are a light-absorbing colored molecule
Tlylakoids are a saclike body in chloroplast made of photosynthetic membranes that contain photo systems
A stroma is a region outside the thylakoid membrane in chloroplasts
NADP+ (nicotinamide adenine dinucleotide) is a electron carrier involved in glycolysis
Light-dependent reactions are reactions of photosynthesis that use energy from light to produce ATP and NADPH
What do light-dependent reactions do?
They produce oxygen gas and converts ADP and NADP+ inot energy carriers ATP and NADPH
ATP synthase is a large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
The Calvin Cycle are reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars
What does the Calvin Cycle use and produce?
It uses ATP and NADPH from the light-dependent reactions
It produces high-energy sugars

Chapter 9-Cellular Respiration

A calorie is the amount of energy needed to raise temperature of 1g of water 1 Celsius Degree
Cellular respiration is the process that releases energy by breaking down food molecules in the presence oxygen
What is the equation for C.R?
6O2 + C6H12O66CO2 + 6H2O + Energy
oxygen + glucose Carbon dioxide + water + energy
Glycolysis is the process in which 1 molecule of glucose is broken in half, producing 1 molecule of pyruvic acid (a 3-carbon compound). Takes place in the cytosol. It makes 2 ATP and loads buses (NAD+  NADH).
6 glucose goes in and 2 ATP, 2 buses filled, 2 pyruvic made
NAD+ is an electron carrier in the process of glycolysis
Fermentation releases energy from food molecules in the absence of oxygen
What are the 2 main types of fermentation?
Alcoholic
Lactic Acid
What does Alcoholic fermentation involve and what is its chemical equation?
Yeasts and other organisms
Pyruvic acid + NADH alcohol + CO2 + NAD+
What does Lactic Acid involve and what is its chemical equation?
Muscles
Pyruvic acid + NADH lactic acid + NAD+
A stage of C.R. is the Kreb’s Cycle. During the Kreb’s Cycle, pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions. It takes place in the matrix (middle area of the mitochondrion). The Kreb’s Cycle generates up to 2 ATP.
Acetyl and CO2 is thrown out in beginning of cycle, extra go on buses
Recharges ATP
Aerobic means to require oxygen
After the Kreb’s Cycle comes the Electron Transport Chain (ETC). The ETC uses the high-energy electrons from the Kreb’s Cycle to convert ADP into ATP. ATP synthase is involved with converting ADP into ATP. Electrons power H+ ions to power the ATP synthase, which makes ATP. The electrons go along the chain (of proteins) on NADH and FADH2.

Chapter 10- Cell Growth and Division

What problems does growth cause for cells?
The larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell has moving enough nutrient and wastes across the cell membrane
Cell division is a process by which a cell divides into 2 new daughter cells
Surface area of a cell = (length x width x 6)
Volume of a cell = (length x width x height)
Ratio of surface area to volume = SA divided by V =?:?
Chromatids are one of two identical sister parts of a duplicated chromosome
Centromere is an area where the chromatids of a chromosome are attached
Interphase is the period of the cell cycle between cell divisions
What happens during the cell cycle?
A cell grows, prepares fro divisions, and divides to form 2 daughter cells each of which then begins the cycle again
How do biologist divide the events of mitosis?
They divide mitosis into 4 phases

Prophase
Metaphase
Anaphase
Telophase

Prophase is the 1st and longest stage of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on opposite sides of the nucleus
Centrioles are one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope
Spindles are fanlike microtubules structures that help separate the chromosomes during mitosis
Metaphase is the 2nd phase of mitosis, during which the chromosomes line up across the center of the cell
Anaphase is the 3rd phase of mitosis, during which the chromosome pairs separate and move towards opposite poles
Telophase is the 4th and final stage of mitosis, during which the chromosomes begin to disperse into a tangle of dense material
Cytokinesis is the division of the cytoplasm during cell division
Cyclin is one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells
Cancer is a disorder in which some of the body’s own cells lose the ability to control growth
What happens with cancer in cells
Cancer cells do not respond to the signals that regulate the growth of most cells. As a result, they form masses of cells called tumors that can damage the surrounding tissues

Promoters are the regions of DNA that indicates to an enzyme where to bind to make RNA
Introns are intervening sequences of DNA; does not code for a protein
Exons expressed sequence of DNA; codes for a protein
Codons are 3-nucleotide sequences on a mRNA that codes for a single amino acids
Translation is the decoding of a mRNA message into a polypeptide chain
During which, the cell uses info from mRNA to produce proteins
Anticodon is a group of 3 bases on a tRNA molecule that are complementary to an mRNA codon
Mutation is the change in a DNA sequence that affects genetic info
What do gene mutations result from?
Results from changes in a single gene. Chromosomal mutations involve changes in whole chromosomes
Point mutations are mutations that affect a single nucleotide, usually by substituting one nucleotide for another
Frame-shift mutations are mutations that shift the reading frame of the genetic message by inserting or deleting a nucleotide
An operon is group of genes operating together
How are lac genes turned off?
They are turn off by repressors and turned on by the presence of lactose
An operator is a region of chromosome in a operon to which the repressor binds when is turned off
What is Eukaryotic Gene Regulation?
Most Eukaryotic genes are controlled individually and have regulatory sequences that are much more complex than those of the lac operon

Hox genes are a series of genes that control the organs and tissues that develop in various parts of an embryo

Chapter 12- DNA & RNA