Honors Biology - Final Exam

osmosis

the movement of water across a membrane from a region of greater concentration to a region of lesser concentration; the diffusion of water

diffusion

the random movement of particles from a region of greater concentration to a region of lesser concentration

draw and label the diffusion diagram

steps of diffusion (shown in the diagram)

the membrane is permeable to oxygen; oxygen moved from a region of greater concentration to a region of lesser concentration; oxygen moved from a region of greater concentration to a region of lesser concentration; equilibrium

facilitated diffusion

process used for molecules that cannot diffuse rapidly through the membrane; the movement of these kinds of molecules across the membrane is assisted by specific proteins in the membrane called carrier proteins

example of something that uses facilitated diffusion

glucose

steps of facilitated diffusion

the carrier protein binds to the molecule it transports; the carrier protein changes shape; the molecule is transported across the membrane; on the other side of the membrane, the molecule is released from the carrier protein, and the carrier protein returns to it's original shape

ion channels

some ions are not soluble in lipids but cannot defuse across the lipid bilayer without assistance and the ion channels will provide a passageway through the cell membrane; each type of ion channel is usually specific for one type of ion; some ion channels are always open and others are gated that open or close to allow ions through or stop their passage

equilibrium

when there is an equal amount of particles on both sides

osmotic balance

when the amount of water entering and leaving the cell membrane is the same

plasmolysis

the shrinking of a cell due to a hypertonic solution; examples: egg in syrup, wilted plants

cytolysis

the bursting of a cell due to a hypotonic solution; examples: egg in hot water, swelling from an injury

hypotonic solution

a solution that contains a lower concentration of solute and more water than the cell placed in it, water will enter the cell, causing the cell to swell and possibly burst

draw and label BEFORE and AFTER the hypotonic solution

isotonic solution

one that has the same concentration of dissolved substances as the cell placed in it, therefore no net gain or loss of water

draw and label an isotonic solution

hypertonic solution

a solution that contains a higher concentration of solute and less water than the cell placed in it, causing water to leave the cell and causing it to shrink

draw and label BEFORE and AFTER a hypertonic solution

difference between endocytosis and exocytosis

endocytosis is the process of taking in materials that are too large to enter by passive transport, while exocytosis is the process of releasing materials that are too large to enter by passive transport

draw and explain the endocytosis diagram

endocytosis steps (shown in the diagram)

the particle is too large to enter; the cell membrane surrounds the particle and forms a pocket; the cell membrane pinches closed and forms a vacuole

draw and explain the exocytosis diagram

exocytosis steps (shown in the diagram)

the large particle is in a vacuole; the vacuole moves to the cell membrane; the cell membrane opens and the particle leaves

all characteristics of the sodium potassium pump

1. involves a carrier protein
2. occurs in animal cells only
3. the pump works to maintain homeostasis
4. it moves against the concentration gradient
5. 1/3 of the energy expended by an animal cell at rest is used for this pump
6. important for muscle contractions, your heartbeat, and your electrical current
7. it is how the nervous system works to send nerve impulses
8. when the pump is functioning normally, there is a high concentration of Na+ ions on the outside and a high concentration of K+ ions on the inside
9. the pump moves 3 Na+ ions outside the cell for every two K+ ions it moves into the cell
10. at top speed, the pump can transport 450 Na+ ions and 300 K+ ions per second

all steps of the sodium potassium pump

1. three Na+ ions located in the cytoplasm bind to the carrier protein
2. a phosphate group is removed from ATP and binds to the carrier protein
3. the binding of the phosphate group changes the shape of the carrier protein, allowing the Na+ ions to be released outside the cell membrane
4. two K+ ions located outside the cell bind to a carrier protein
5. a phosphate group is removed from ATP, changing the shape of the carrier protein and the K+ ions are released into the cell

passive transport

the movement of substances across the membrane without the use of energy; examples: diffusion, osmosis

active transport

the movement of materials across the membrane that requires energy (ATP); examples: endocytosis, exocytosis

concentration gradient

a difference in the concentration of molecules across space; always temporary

turgor pressue

pressure exerted by water on the cell wall

parts of the fluid mosaic model

1. consists of a lipid bilayer with 2 sheets of phospholipids arranged tail to tail
2. proteins are found both inside and outside the cell membrane
3. carbohydrates are found only on the outside
4. cholesterol is located between the fatty acids

reasons why ATP is important

1. it stores and controls the release of energy
2. it is used for the synthesis of molecukes
3. it is used in muscle contractions
4. it is used in the conduction of nerve impulses
5. it provides energy for active transport

what ATP stands for, what it is, it’s symbol

Adenosine Triphosphate; an organic compound, cell energy; A - P ^ P ^ P

the type of bonds between the phosphate groups in ATP and why they are easily broken

high energy bonds; covalent bonds that are more unstable than the other bonds in ATP because the phosphate groups are close together and have a negative charge, making them easier to break

where is ATP made

in the mitochondria

the building blocks of ATP and how they are combined

1 adenine, 1 ribose, 3 phosphate are combined by dehydration synthesis

draw and label the ATP energy cycle (cycle of energy storage and release)

anabolic reaction

the buildup of substances used for growth, maintenance, and repair; examples: amino acids to proteins, monosaccharides to carbohydrates

catabolic reaction

the breakdown of molecules to release energy; examples: digestion, cellular respiration

enzymes

organic protein substances that make it possible for the chemical reactions of life to go on in living cells; examples: maltase, lipase

coenzymes

organic substances, but not proteins, that enable enzymes to perform their catalytic functions; not catalysts; examples: ATP, Vitamin A

all characteristics of enzymes

1. a catalyst is a substance that affects a reaction by speeding it up without itself being changed
2. for each step of a reaction, there’s a particular enzyme that brings it about
3. enzymes enter a chemical reaction only temporarily
4. the names of enzymes usually end with the suffix -ase and are derived from the substrate’s name (enzymes named before the 1900s do not end in -ase, like pepsin)
5. all enzymes are made by the cell but many leave the cell to react with others; -ex: pepsin is made by cells of glands in the stomach wall but leaves to mix with food in the stomach
6. a single enzyme can catalyze thousands of substrate reactions each second because the enzyme is not changed by the reaction, there is a different enzyme for each step of a reaction, and they only enter temporarily
7. enzymes speed up reactions in a cell without requiring high temperatures; they work best at body temperature (98.6 F)
8. most human enzymes work best at a ph of 6-8
9. enzymes can act as an acid or base by donating or accepting hydrogen ions
10. enzymes lower a reactions’ activation energy, which speeds up the reaction
11. some enzymes need substances called coenzymes to function
12. enzymes can bring about synthesis (smaller to larger) -ex: 2 amino acids to a dipeptide
13. enzymes can bring about hydrolysis (large things broken down to smaller things) -ex: disaccharide to 2 monosaccharides
14. the Lock and Key Hypothesis states that the active site of an enzyme fits like a puzzle into the reactive site of the substrate
15. the Induced Fit Theory states that the active site of the enzyme must adjust to fit the reactive site of the substrate
16. metabolic pathways

substrate

the substance an enzyme acts upon; examples: maltose, sucrose

ph scale

0-6 are acids, 7 is neutral, 8-14 are bases

activation energy

the minimum energy needed for a process to occur

draw and label the Lock and Key Hypothesis

draw and label the Induced Fit Theory

metabolism

a sum of all the chemical reactions occurring inside an organism

reactants versus products

what you start with versus what you end with

draw and label a Metabolic Pathway and answer questions

DNA’s structure

1. consists of two strands which wind together to form a double helix (2 nucleotide strands)
2. anti-parellel
3. the sides of the ladder are made up of an alternating phosphate group and a 5-Carbon sugar called deoxyribose
4. the middle rungs of the ladder are made up of nitrogen bases held together by weak hydrogen bonds
5. nucleotides are the building blocks

RNA’s structure

1. single-stranded
2. the sides of the RNA are made up of an alternating phosphate group and a 5-Carbon sugar called ribose
3. RNA has 4 nitrogen bases: Adenine, Guanine, Cytosine, Uracil

complimentary bases

bases that bond together; in DNA: Adenine and Thymine, Cytosine and Guanine; in RNA: Adenine and Uracil, Cytosine and Guanine

what makes up a nucleotide in DNA? In RNA?

in DNA: deoxyribose sugar, phosphate, and a base of either Adenine, Thymine, Cytosine, or Guanine; in RNA: ribose sugar, phosphate, and a base of either Adenine Uracil, Cytosine, or Guanine

purines; purines in DNA and in RNA

double rings made up of 6-Carbon and 4-Nitrogen; in DNA: Guanine and Adenine; in RNA: Guanine and Adenine

pyrimidines; pyrimidines in DNA and in RNA

consist of a single ring made up of 4-Carbon and 2-Nitrogen; in DNA: Thymine and Cytosine; in RNA: Uracil and Cytosine

function of DNA

carries the genetic code; contains the genetic material

function of RNA

protein synthesis

function of mRNA

it carries the message or code from DNA in the nucleus to the cytoplasm

function of tRNA

it picks up and carries amino acids to the mRNA at the ribosomes

function of rRNA

makes up the ribosomes, but it's role in protein synthesis is not known; involved in protein synthesis

draw tRNA

the shape of mRNA

a single, uncoiled strand

DNA replication

a complete copy of DNA is made before a cell divides; occurs in the nucleus

all steps of DNA replication

1. DNA molecule unwinds with the enzyme DNA Helicase and splits along the weak hydrogen bonds -each strand of the DNA will serve as a template or guide for the assembly of complimentary bases
2. new complimentary nucleotides are added by an enzyme called DNA polymerase
3. an identical strand is made

draw the steps of DNA replication

transcription

the making of mRNA from DNA; occurs in the nucleus

all steps of transcription

1. RNA Polymerase initiates transcription by binding to specific regions of DNA called promoters
2. when RNA polymerase binds to a promoter, the DNA molecule unwinds and separates along the weak hydrogen bonds
3. only one of the separated DNA chains called the template is used for transcription
4. RNA nucleotides are added to complimentary bases on one of the two strands of DNA by RNA Polymerase
5. Transcription continues and one nucleotide is added at a time until the RNA Polymerase reaches a DNA region called the termination signal

-at the termination signal, RNA Polymerase releases the newly formed mRNA and DNA


6. mRNA will move through the pores of the nuclear membrane where it will direct protein synthesis

translation

the process of assembling proteins from information encoded in mRNA; takes place in the cytoplasm

all steps of translation

1. mRNA will temporarily bond to the ribosomes
2. a start codon, AUG, signals a ribosome to start reading the mRNA
3. the ribosomes appear to move along the mRNA and point out each codon to tRNA
4. one end of the tRNA can bond to a codon on the mRNA temporarily
5. the amino acids brought into position by the tRNA join the last amino acid by a covalent bond called a peptide bond, forming a chain that will eventually separate from the tRNA
6. the amino acids continue to be added until the ribosomes reach a stop codon
7. the proteins are synthesized in the cytoplasm and the chromosomes, carrying the hereditary material, remains in the nucleus

codons

three mRNA bases; examples: UAA, CCC

anticodons

three tRNA bases; no code

be able to go from DNA to mRNA to tRNA; find the number of amino acids

mutation

a mistake in the DNA

termination signal

ends transcription and releases the mRNA and DNA

start codon

AUG; signals a ribosome to start reading the mRNA

stop codon

UAA, UAG, UGA; mRNA bases; signal the ribosomes to stop reading the mRNA and the protein is complete

promoters

mark the beginning of the DNA chain that will be transcribed

template

one of the separated DNA chains used for transcription; serves as a guide for the assembly of complimentary bases

cellular respiration

a complex process in which cells break down organic compounds to form ATP (carbohydrates are the biggest group broken down)

cellular respiration equation

C6H12O6 + 6O2 -----→ 6H2O + 6CO2 + ATP

glycolysis

the breakdown of glucose into pyruvic acid

key words in glycolysis

phosphate, glucose, 6-Carbon, fructose, 3-Carbon, G3P, oxidized

key words in the Krebs Cycle

2-Carbon, 4-Carbon, 5-Carbon, 6-Carbon, hydrogen, CO2

key words in the electron transport chain

electron, NADH, FADH2, protons, H+ ions, carrier protein, redox reactions, channel, protein, chemosis, oxygen

what happens in the transition reaction

Before the Krebs Cycle can begin, pyruvic acid combines with a coenzyme A to form a 2-Carbon compound called acetyl CoA (acetic acid)

where does glycolysis occur

in the cytosol of the cytoplasm

where does the transition reaction occur

in the matrix of the mitochondria

where does the Krebs Cycle occur

in the matrix of the mitochondria

where does the electron transport chain occur

in the cristae of the mitochondria

final products of glycolysis

2 pyruvic acid, 2 ATP, 2NADH2

final products of the transition reaction

2 acetic acid, 2CO2, 2NADH

final products of the Krebs Cycle

2 ATP, 4CO2, 6NADH, 2FADH2

final products of the ETC

6 water, 34 ATP

what product begins glycolysis

glucose

what product begins the transition reaction

pyruvic acid, oxygen

what product begins the Krebs Cycle

acetic acid

what products begin the ETC

NADH and FADH2

fermentation

glycolysis followed by a conversion of pyruvic acid into some other end product

cristae

membranes in the mitochondria; where chemical reactions take place

matrix

the space inside the inner membrane of the mitochondria