Biology EOC

Organic Molecules

Organic compounds contain carbon and are found in all living things.

Carbohydrates

Major source of energy and include sugars and starches
made up of carbon

Proteins

Nitrogen-containing compounds made up of chains of amino acids
20 amino acids can combine to form a great variety of protein molecules
can compose enzymes

Lipids

Water-insoluble (fats and oils)
made up of carbon

composed of glycerol and fatty acid
provide insulation

store energy

Nucleic Acids

Direct the instruction of proteins
genetic information an organism receives from its parents
two types: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid)

Chloroplast

Captures solar energy for photosynthesis (plant cells

Golgi Body

Package

Lysosomes

Digests excess products and food particles

Mitochondria

Transform energy through respiration

Nucleus

Contains DNA which controls cellular activities

Ribosome

Produce proteins

Vacuole

Store substances

Cell (plasma) membrane

Phospholipid bilayer that protects and encloses the cell

controls transport

maintains homeostasis

Cell wall

Rigid second layer that protects and encloses the cell (plant cells and some bacteria)

Cytoplasm

Fluid-like substance that contains various membrane-bound structures (organelles) that perform various functions

Endoplasmic Reticulum

Site of chemical reactions

• ROUGH: contains ribosomes
• SMOOTH: lipid production

Cytoskeleton

Provides internal structure

• MICROFILAMENTS: fibers
• MICROTUBULES: cylinders

Unicellular

Organism that exists as a singular

Multicellular

Organism that exists as specialized groups of cells

cells are organized into tissues that perform the same function

tissues form organs and organs make up an organ system

Prokaryote

Has nuclear material in the center of the cell

no membrane-bound organelles

found in bacteria and blue-green bacteria

Eukaryote

Contain a clearly defined nucleus enclosed by a nuclear membrane and membrane-bound organelles

found in plants

animals

Cell Theory

-The cell is the basic unit of life.
-All organisms are composed of cells
-All cells come from pre-existing cells.

Cell Specialization

-cells >>>> tissues >>>> organs >>>> organ systems >>>> organism
-each cell performs a specific function for each tissue or organ
-as cells mature

Passive Transport

Movement of substances across the plasma membrane without the use of the cell's energy (with the concentration gradient)

Diffusion

Movement of substances across the plasma membrane from an area of high concentration to an area of low concentration

Osmosis

Diffusion of water across the plasma membrane from areas of high concentration to areas of lower concentration

Facilitated Transfusion

A carrier molecule embedded in the plasma membrane transports a substance across the plasma membrane following the high-to-low concentration gradient

Active Transport

Movement of substances across the plasma membrane that requires the use of the cell's energy and carrier molecules

substances are moving from an area of low concentration to an area of higher concentration (against the concentration gradient)

Endocytosis

Large particles are brought into the cell

Exocytosis

Large particles leave the cell

Homeostasis

Internal equilibrium

the plasma membrane regulates what enters and leaves the cell

a selectively permeable membrane only allows certain substances to pass through

Hypotonic

Water moves in

cell bursts

Hypertonic

Water moves out

cell shrivels

Isotonic

No net movement

cell maintains equilibrium

Homeostasis

Self-regulating mechanism that maintains internal conditions (with individual cells and within organs

Biochemical Reactions

Chemical bonds are formed and broken within living things creating chemical reactions that impact the ability to maintain life and carry out life functions

Fermentation

When cells are not provided with oxygen in a timely manner

glucose is broken down

there are two types of fermentation

Lactic Acid Fermentation (muscle cells)

Glucose ==> Lactic Acid + 2ATP

Alcoholic Fermentation (plant cells)

Glucose ==> CO2 + Alcohol + 2ATP

Cellular Respiration

Food molecules are converted to energy

there are three stages to cellular respiration

the first stage is called glycolysis and is anaerobic (no oxygen is required)

the next two stages are called the citric acid cycle and the electron transport chain and are aerobic (oxygen is required)
C6H12O6 + 6O2 ==> 6CO2 + 6H2O + ENERGY (36 ATP)

Photosynthesis

Plant cells capture energy from the Sun and convert it into food (carbohydrates)

plant cells then convert the carbohydrates into energy during cellular respiration

the ultimate source of energy for all living things is the Sun (in Chemosynthesis

organisms use sulfur or nitrogen as the main energy source)
6CO2 + 6H2O + ENERGY(from sunlight) ==> C6H12O6 + 6O2

ATP

ATP is a molecule that stores and releases the energy in its bonds when the cell needs it

removing a phosphate group (P) releases energy for chemical reactions to occur in the cell and ATP becomes ADP

when the cell has energy

the energy is stored in the bond when the phosphate group is added to the ADP
ATP ⇔ ADP + P + ENERGY

Aerobic Respiration

-Requires the presence of oxygen
-Release of energy from the breakdown of glucose (or another organic compound) in the presence of oxygen
-Energy released is used to make ATP

Anaerobic Respiration

-Occurs in the absence of oxygen
-Breakdown of food substances in the absence of oxygen with the production of a small amount of energy
-Produces less energy than aerobic respiration
-Often called fermentation
-Seen as an adaptation for organisms that live in environments that lack oxygen

Cellular Respiration

Food Broken Down
Energy from Glucose Released
Carbon Dioxide given off
Oxygen taken in
Produces Carbon Dioxide and Water
Does not require Light
Occurs in ALL Living Cells
Organisms often called Heterotrophs

Photosynthesis

Food Synthesized
Energy from Sun stored in Glucose
Carbon Dioxide taken in
Oxygen given off
Produces Sugars (Glucose) from PGAL
Requires Light
Occurs only in presence of Chlorophyll
Organisms called Autotrophs

Chemosynthesis

Food Synthesized
Energy from Methane or Inorganic Material
(ex: H gas or Hydrogen sulfide)
Organisms often called chemotrophs
Organisms called extremophiles
Live in environments without oxygen
Anaerobic Bacteria
Habitats: hydrothermal vents

Enzymes

Special proteins that regulate nearly every biochemical reaction in the cell. Different reactions require different enzymes.
Function:
-Provide energy to cells
-Build new cells
-Aid in digestion
-Break down complex molecules ("substrate" = reactant)
-Catalysts (speed up chemical reactions without being used up or altered)
-Factors that affect enzymes: pH

DNA and RNA

-Nucleic acids composed of nucleotides
-Nucleotides composed of:
Phosphate group
Sugar
Nitrogenous base

DNA

Deoxyribonucleic acid
Double-stranded

RNA

Ribonucleic acid
Single-stranded
Leaves the nucleus
Nitrogenous bases: adenine

Messenger - mRNA

Transfer - tRNA)
Leaves the nucleus to carry out functions in cytoplasm
Transcription:
(mRNA is made from one strand of DNA

carries message to ribosomes)
Translation:
(mRNA translated into a protein at the ribosomes

tRNA transfers amino acids from cytoplasm to ribosomes)

Asexual Reproduction

A single parent produces one or more identical offspring by dividing into two cells - mitosis (protists

produces large numbers of offspring

• offspring are clones of parents (genetically identical)
• common in unicellular organisms

good for stable environments

• budding

Sexual Reproduction

Pattern of reproduction that involves the production and fusion of haploid sex cells

haploid sperm from father fertilizes haploid egg from mother to make a diploid zygote that develops into a multicellular organism through mitosis

• results in genetic variation (diversity)
• common in multicellular organisms (external or internal fertilization)

good for changing environments

• slow process (high energy requirement) - produces low number of offspring
• meiosis = formation of sex cells (gametes)

Cell Division

-process of copying and dividing the entire cell
-the cell grows

Types of Cell Division

Binary fission (bacteria and fungi)

Mitosis

Cell cycle consists of interphase

Interphase

Longest part of cell cycle
Growth

Prophase

Duplicated chromosomes and spindle fibers appear

Metaphase

Duplicated chromosomes line up randomly in center of cell between spindle fibers

Anaphase

Duplicated chromosomes pulled to opposite ends of cell

Telophase

Nuclear membrane forms around chromosomes at each end of cell

spindle fibers disappear

chromosomes disperse

Cytokinesis

Division of plasma membrane

two daughter cells result with exact genetic information
(in plant cells a "cell plate" forms along the center of the cell and cuts the cell in half

cell plate forms new cell walls once the plasma membrane divides)

Meiosis

Consists of two cell divisions

First Meiosis Division

Produces cells containing ½ # of double stranded chromosomes

Second Meiosis Division

Results in formation of four cells
Each cell w/ ½ # of single-stranded chromosomes
(haploid cells)

Sperm

Each primary sperm cell develops into four haploid cells of equal size. As cells mature

Egg

Each primary egg cell develops into one large haploid cell and three smaller haploid cells called polar bodies. The first meiosis division produces one large cell and one polar body. The second meiosis causes the large cell to produce one egg cell and a polar body