Study Guide for Biology H Midterms

DNA definition

Directs all cell activity from the nucleus.

Amino Acid definition

The basic building block of proteins- 20 different types of amino acids.

Anticodon definition

a set of three bases on a tRNA molecule.

Transcription definition

the process of making a strand of mRNA from DNA in the nucleus.

Codon definition

3 letter code on a strand of mRNA that represents a specific amino acid.

Translation definition

the process of making a protein by following the code on the mRNA.

mRNA definition [Messenger RNA]

a molecule that is made in the nucleus, then travels into the cytoplasm to begin protein synthesis.

tRNA definition

transports amino acids to the mRNA where the protein is being made and matches the anticodon with the codon on the mRNA.

Protein definition

a type of large molecule in living things that are made of a chain of amino acids.

Nucleotide definition

the basic building blocks of either DNA or RNA that is made of a sugar group, a phosphate, and a nitrogenous base.

Substitution definition (in a DNA or RNA chain)

When a base in a DNA/RNA chain is substituted for another base.

Deletion definition (in a DNA or RNA chain)

When a base in a DNA/RNA chain is removed/lost, causes a "frameshift" and can cause visible mutations.

Insertion definition (In a DNA or RNA chain)

When a base is added into a DNA/RNA chain. Causes a "frameshift" and can cause visible mutations.

Neutral/Silent mutation

When a DNA sequence is changed (insertion, deletion, or substitution), but no visible mutations occur.

What part of a cell translates RNA into proteins?

A Ribosome

DNA -> RNA -> Protein This process is called...?

Central Dogma

What are the three parts of a nucleotide?

Nitrogenous base, Phosphate, and deoxyribose sugar.

What are the four nitrogenous bases?

Adenine, Cytosine, Thymine, and Guanine. (Also Uracil, but only for RNA translation.)

Daughter Strand

The new strand after DNA replication.

Okazaki Fragment

"Chunks" of bases being put onto the lagging strand.

What keeps the backbone of DNA together?

Hydrogen Bonds.

Leading Strand

The parent strand that is added to continuously during DNA replication.

Lagging Strand

The parent strand that is not added to continuously.

Replication fork

Where DNA is separated.

Helocase

"Unzips" DNA.

DNA Polymerase

Builds daughter strand by adding bases.

Semi-Conservative Replication

Made of one "conserved" strand and one new strand.

Evolution

Change in an organism over a long period of time.

What are the 8 characteristics of life?

1. Maintains Homeostasis (maintains a stable "inner environment")

2. Responds to Stimuli (Any change in environment, i.e. pupils expanding when a light is shut off, etc)

3. Can Evolve

4. Reproduces

5. Growth & Development (gets bigger, its functions can change, etc)

6. Displays Organization (cells build in a predictable and orderly fasion)

7. Has a Metabolism

8. Made of Cells

Abiotic

something that's non-living (can be determined with 8 characteristics of life).

Bionic

Something living (can be determined with 8 characteristics of life).

Feedback Loops

The process the brain (or anything) uses to processes information and respond to it. Can be positive (i like the outcome, continue to do what I'm doing) or negative (i don't like the outcome, change what I'm doing).

Positive Feedback loop i.e. Wound Repair

Negative Feedback loop i.e. Sweating/shivering (lowering/raising temperature)

Parts Of a Feedback Loop

1. Stimuli (i.e., temperature outside increases.

2. Variable (what's being monitored- in this case, its temperature.)

3. Sensor (Taking in info [five senses] i.e. noting a change in temp and sending this info to the brain.)

4. Control (Brain processes info and decides response.)

5. Effector (Response to stimuli. In this case, you would sweat if you got too hot.)

Set Point

Whatever the normal level for something is. (i.e. Humans are around 98.6 degrees fahrenheit usually.)

Properties of Water

1. Its cohesive (water molecules stick to other water molecules --> makes surface tension)

2. Its adhesive (water molecules can stick to other non-water molecules)

3. It's a polar molecule (has an uneven charge)

4. It's a universal solvent.

5. It has a high heat capacity. (It can heat up a good amount before boiling)

6. It gives off energy/takes energy in very slowly.

7. Forms hydrogen bonds

8. It's more dense then ice.

PH Scale

0 is acidic

7 is neutral

14 is basic

more OH --> basic

more H --> Acidic

Solution (mixture, not equation)

One part (a solute) is dissolved into another (solvent.) Very hard to separate.

Solute

thing that dissolves in solvent

Solvent

thing that dissolves the solute

Does an acid donate or accept hydrogen?

It donates

Does a base donate or accept hydrogen?

it accepts

What are the 6 most important molecules / elements?

1. Carbon

2. Hydrogen

3. Nitrogen

4. Oxygen

5. Phosphorus

6. Sulfur

THINK CHNOPS!

Carbohydrates

polysaccharide

one monomer --> monosaccharide

made of the elements C:H:O (1:2:1 ratio)

Lipids

triglyceride (when it looks like an E)

made of fatty acids

made of the elements C:H:O

Proteins

polypeptide

peptide

made of amino acids

made of the elements C:H:O:N:(S) "S" is sometimes found- not usually

Nucleic Acids

DNA/RNA

Nucleotide

made of the elements C:H:O:N:P

Dehydration synthesis

the creation of a macromolecule when macromolecules form

Hydrolysis

requires a water molecule to break bonds.

hydro--> water

lysis--> breakdown

what type of energy do carbs give you?

quick energy!

what type of energy do lipids give you?

low, long term energy.

what type of energy does protein give you?

low, long term energy

what type of energy do nucleic acids give you? (Trick question!)

Only hold genetic info- no energy given

Enzymes

Specialized proteins (Amino acids) used to speed up chemical reactions

[i.e. digestion, breaking up macromolecules]

Enzymes use a KEY AND LOCK model. What are the different parts on an enzyme?

the active site (where the substrate connects to the enzyme), the substrate (the chemical reaction needing to be sped up, and the enzyme. The products are what is made by the chemical reaction & enzyme. IF THEY ARENT IN THE RIGHT PH OR TEMP THE MODEL WILL NOT WORK.

Unsaturated fatty acid

has room for more bonds- can break and bend

Saturated fatty acid

cannot add more bonds- all possible bonds have already been made.

Inhibitors

things that might stop the enzyme from connecting with its specific substrate

Competitive inhibitor

direct competition (blocks active site)

Allosteric Inhibitor (indirect/noncompetitive inhibitor)

Changes the shape of the active site by attaching itself to the enzyme.

Prokaryote

a cell with no nucleus- smaller, less evolved (i.e. bacteria cell)

Eukaryote

A cell with a nucleus- more evolved and complex (i.e. plant or animal cell)

Cell Theory

1. Cells are the building blocks of life

2. All living things are made up of cells

3. All cells come from pre-existing cells

The Cell Membrane

1. semi-permeable (allows certain molecules to enter/exit cell

2. a fluid mosaic model (can change shape, made of different molecules)

Phospholipid bilayer.

Made like a sandwich

Phosphate (hydrophilic)

Lipids (hydrophobic)

Phosphate (hydrophilic)

How do things move across a membrane?

DIFFUSION!!!!!

Diffusion

Any particles moving from an area of high concentration to low concentration. Uses NO ENERGY.

Simple Diffusion

Something small can go through the membrane- gasses, dissolvable

Facilitated Diffusion

will open in response to a chemical/electrical signal

Osmosis

The diffusion of water.

Hypertonic

More solute (Hyper- above, more)

Hypotonic

Less solute (hypo- below, less)

Isotonic

Equal part solute and water. (Iso- Equal)

Why is it important for a cell to be small?

A small cell allows for waste to be removed/nutrients to be brought in and get to their destination more efficiently than if the cell was big. If a cell is too small, it might not have enough room for the necessary organelles.

What are the parts of a cell cycle?

Interphase (G1, S Phase, and G2) and Mitosis.

What occurs during G1 and G2?

Growth and development of a cell.

What occurs during S Phase?

Synthesis/DNA replication [also called duplication]

What are the stages of Mitosis?

Prophase

Metaphase

Anaphase

Telophase

What occurs during Prophase?

The nuclear membrane dissolves and DNA condenses into chromosomes.

What occurs during Metaphase?

Sister chromatids (Chromosomes) line up in the middle of the cell to form a line.

Centrosomes also send out microtubules that connect to the centromeres of the chromosomes.

What occurs during Anaphase?

The sister chromatids are pulled away from each other- one on each side of the cell.

What occurs during Telophase?

Two cells start to form (elongation begins and "pinching" occurs in the middle.) The nucleus reforms. Cytokinesis IS NOT A PART OF TELOPHASE! They occur at the same time but AREN'T a part of the same process.

Cytokinesis

The splitting of the cell. (NOT A PART OF MITOSIS)

rRNA [Ribosomal RNA]

Makes up the ribosome.

What are the phases of Meiosis?

PMAT |

Prophase |

Metaphase |

Anaphase |

Telophase |

PMAT ||

Prophase ||

Metaphase ||

Anaphase ||

Telophase ||

What occurs during Prophase | and ||?

Prophase | --> Crossing over happens between homologous chromosomes, nucleus dissolves

Prophase || --> Nucleus dissolves

What occurs during Metaphase | and ||?

Metaphase | -- > Homologous Chromosomes meet in the middle of the cell

Metaphase || -- > Sister Chromatids meet in the middle of the cell

What occurs during Anaphase | and ||?

Anaphase | --> Homologous chromosomes move away from each other

Anaphase || --> Sister Chromatids move away from each other

What occurs during Telophase | and ||?

Telophase | & || --> Splits cell apart

How many cells do you end up with in Meiosis / what are some characteristics they have?

You end up with four unique daughter cells with 23 chromosomes each.

Why is Meiosis so important?

It's the sole reason for genetic information.

Diploid/2N

a cell that contains 2 copies of each chromosome (Has 46 chromosomes)

Haploid/N

a reproductive cell with 23 chromosomes.

Zygote

A newly fertilized egg

Circulatory System

(aka cardiovascular system) This system works to move blood around the body. It consists of the heart, blood, and blood vessels. It transports substances such as oxygen, carbon dioxide, and nutrients in the body.

Nervous System

the network of nerve cells and fibers that transmit nerve impulses between parts of the body.

Brain, spinal cord, and neurons.

Respiratory System

Exchanges O2/CO2

Mouth, Nose, throat, pharynx, larynx, bronchi, alveoli, lungs

Digestive System

Breaks down / takes in nutrients

mouth, esophagus, liver, stomach, pancreas, gallbladder, intestines

Excretory/Urinary System

removes waste from body

Excretory:

kidneys

bladder

Urinary:

liver

skin

lungs

What are the main five body systems?

Nervous, Excretory/urinary, digestive, respiratory, and circulatory.

X-Linked definition

a gene located on the X chromosome