Semester Exam Review

Biomolecules

Monomer / Polymer / Function
/ Amino acid / protein / Builds muscle, controls rate of reaction (enzymes), product of translation
/ monosaccharide / carbohydrate / Quick energy
/ fatty acid / lipid / Protection for the cell (Cell membranes), long term energy storage, insulation
/ nucleotide / nucleic acid / Genetic material, controls cell processes, contains instructions for building proteins

Homeostasis

Define homeostasis and give a real life example.

maintaining a stable internal condition – sweating, blood clotting, etc.

Enzymes

Enzymes are biological ____catalysts______. This means that they lower the __activation_energy required to start a chemical reaction and they _speed up _ the reaction. Enzymes are __proteins_ built from amino acids. After they complete a reaction they continue to __affect___ other reactions; they are _not__ changed by the reaction.The substrate and enzyme fit together like a _lock__ and ___key___.

Cell Types

Label the following pictures as prokaryotic or eukaryotic cells.

Cell Type / Similarities / Differences
Prokaryotes/Eukaryotes / Type of cells; contain cell membrane, DNA, and ribosomes; respond to stimuli; use energy / Prokaryotes have no nucleus or other organelles; Eukaryotes are larger and more complex

Molecule Transport

Label the above pictures as an example of osmosis or diffusion. For the osmosis picture, tell which direction the water will flow.

In both osmosis and diffusion molecules move from a __high___ to a ____low______concentration.

Test tube A contains a ___isotonic__ solution, which means that the cell will __not change______. Test tube B contains a ___hypotonic___ solution, which means the cell will ___grow_. Test tube C contains a __hypertonic_ solution, which means the cell will ____shrink____.

DNA

Replication / Transcription / Translation
Description / Making an identical copy of a DNA strand / Making an mRNA copy of the DNA instructions / Creating a protein (polypeptide) out of amino acids using the mRNA strand
Example: Original DNA
strand TAA CGA GCT / TAA CGA GCT / AUU GCU CGA / Isoleucine – alanine - arginine
Location (in cell) / Nucleus / Nucleus / Ribosome

DNA structure

Label the following diagrams: sugar-phosphate backbone, nitrogenous bases, phosphate, sugar, hydrogen bond, phosphate group, deoxyribose, nitrogenous base

Mutations

DNA / mRNA / Amino Acids / Type of mutation
Original Strand / TAA CGA GCT / AUU GCU CGA / Isoleucine – alanine - arginine / none
Copy 1 / TAA GGA GCT / AUU CCU CGA / Isoleucine – proline - arginine / point
Copy 2 / TAA GCG AGC T / AUU CGC UCG A / Isoleucine – arginine - serine / frameshift

Mutations can be caused by: ____errors in replication, transcription, or translation; environmental factors like radiation, chemical exposure, etc.______

Meiosis/Mitosis

Mitosis / Meiosis
Number of chromosomes / 2N / N
Haploid or Diploid? / Diploid / Haploid
Genetically Identical to parent cell? / Yes / No
Location occurs in an organism / All body cells / Gametes (sex cells)
Crossing over? / No / Yes
Function / Growth & development / Sexual reproduction

Cell Cycle

What happens in each phase of the cell cycle?

G0: resting

G1: cells grows, produces new proteins & organelles

S: DNA replication

G2: new proteins & organelles are produced to prepare for division

M: cell divides

-Prophase: chromosomes are visible

-Metaphase: chromosomes line up along the equatorof the cell

-Anaphase:chromatids split and move away from each other

-Telophase: two new nuclei form

How does cancer affect the cell cycle? ____growth and division continue uncontrolled ______

Sample Questions

An amoeba in a pond engulfs and consumes a paramecium. The amoeba uses which of the following to quickly break down the organic molecules in the paramecium?

A. / enzymes
B. / glucose
C. / polysaccharides
D. / water

The image on this page represents the processes that a cell goes through during mitosis. The parent cell will divide, creating two daughter cells. A student wishes to create a model of the mitotic process within a cell. How many chromosomes should the daughter cells in the model contain?

A Twice as many chromosomes as the parent cell
B The same number of chromosomes as the parent cell
C Half as many chromosomes as the parent cell
D There should not be any chromosomes in the daughter cells.

Which of the following roles does an enzyme play when the body processes sucrose (table sugar) into glucose and fructose?

A. / An enzyme decreases the body’s need for sucrose.
B. / An enzyme increases the amount of sucrose available.
C. / An enzyme increases the rate at which the sucrose breaks down.
D. / An enzyme decreases the amount of fructose and glucose product available.

The diagram to the right represents a process that occurs in the nucleus of a eukaryotic cell.

Which of the following statements describes what is happening in this process?

A. / Molecules of RNA are forming chromosomes.
B. / A molecule of mRNA is directing the production of tRNA.
C. / Molecules of DNA are being packaged for export to the ribosomes.
D. / A molecule of DNA is being replicated to make two identical copies.

The diagram below represents the beginning and end products of a process that occurs in the nucleus of a cell.

Which process does the diagram represent?

A. / recombination
B. / replication
C. / transcription
D. / translation

If an animal cell is placed in distilled water, it will swell and burst. The bursting of the cell is a result of which biological process?

A. / active transport
B. / enzyme activity
C. / osmosis
D. / respiration

Which of the following models most accurately represents the structure of DNA?

Which of the following statements best explains why oxygen diffuses from the alveoli into the blood?

A. / The diaphragm draws oxygen into the alveoli at a rapid speed.
B. / Alveoli cells contain hemoglobin to transfer gases to the blood.
C. / The concentration of oxygen is greater in the alveoli than in the blood.
D. / Red blood cells move one at a time through the capillaries surrounding the alveoli.

Which of the following features of DNA is most important in determining the phenotype of an organism?

A. / the direction of the helical twist
B. / the number of deoxyribose sugars
C. / the sequence of nitrogenous bases
D. / the strength of the hydrogen bonds

A scientist is analyzing a sample of tissue from a plant. Which of the following elements will be most abundant in the sample?

A. / zinc and copper
B. / sodium and chlorine
C. / carbon and hydrogen
D. / magnesium and calcium