Cell And Molecular Biology

what is the smallest living unit?

cell

amino acids

the building blocks of proteins (20 variants)

Mutations

• generate offspring that are less fit for survival than the parent cell

• errors from DNA replication

• generate offspring that are more/just as fit for survival than the parent cell

Evolution

the process of mutation and selection over the course of many generations

Evolution is a process

that can be understood based on the principles of mutation and selection

What is the order of biochemical reactions that control the flow of genetic information?

DNA —> Transcription —> RNA —> Translation —> Protein

Genome

the entire sequence of nucleotides that make up a cells DNA

What is the smallest distance two points can be separated and still resolved with the unaided eye?

200 micrometers

What is the cause of size limits for certain types of cells?

the need for high surface area to volume ratio to support the cell’s metabolic requirements

Resolution

the measure of the clarity of the image being observed, or the minimum distance of two distinguishable points

What is the resolving power of a light microscope limited by?

wavelength

What is the smallest distance two points can be separated and still resolved using light microscopy?

0.2 micrometers

Why is the resolving power of electron microscopy far greater than that of light microscopy?

electron microscopes image specimens using electrons that have a much shorter wavelength than photons

What domains do prokaryotes belong to?

Bacteria and Archaea

What cellular structure is common to all three domains of life?

the plasma membrane

Prokaryotic cells do not possess a

nucleus

What is part of a typical prokaryotic cell?

• DNA

• Cell Wall

• Plasma Membrane

• Ribosomes

How much longer and how much more volume do eukaryotic cells have than prokaryotic cells?

10 times and 1000 times

Nuclear Envelope

made up of two concentric membranes and is continuous with the membrane of the endoplasmic reticulum

What organelle has both an outer and an inner membrane?

Mitochondria

Location of Chlorophyll

in the third most inner membrane called the thylakoids

What do mitochondria consume in the conversion to ADP to ATP?

Oxygen

Mitochondria and chloroplasts cannot function for long when isolated from the cell because they are

endosymbionts

What do motor proteins interact with to provide molecular motion in cells?

cytoskeletal structures

Microtubules are required to pull duplicated chromosomes to opposite poles of dividing cells and such they must

rapidly reorganize

Model Organism Characteristics

• Amenability to genetic manipulation

• ability to grow under controlled laboratory conditions

• rapid rate of reproduction

What bacterial species had a central role in advancing the field of molecular biology?

E. coli

What was the most important feature of C. elegans for the study of apoptosis?

The developmental pathway of each cell in the adult worm was known

Zebrafish are useful in the study of early development because their embryos are

transparent

Microtubules

the thickest of the three components of the cytoskeleton

Microfilaments (actin filaments)

the thinnest of the three components of the cytoskeleton

Intermediate Filaments

fibers that have diameters in the middle range

Atomic Number

number of protons

Atomic Mass

number of protons and neutrons

What subatomic particles can vary between isotopes of the same element?

neutrons

What determines the reactivity of an atom?

the existence of unpaired electrons in the valence shell

Covalent Bond

the sharing of electrons

Ionic Bond

the transfer of electrons from one atom to another

What compound would mimic the effects of another?

one with the same three-dimensional shape as part of the compound

when atoms are equally electronegative they will form

nonpolar covalent bonds

What results from an unequal sharing of electrons between atoms?

a polar covalent bond

what noncovalent interaction will contribute most to the strong/specific binding of two molecules?

electrostatic attractions

What factors influence the length of a covalent bond?

• attractive forces between negatively charged electrons and positively charged nuclei

• the repulsive forces between the positively charged nuclei

• the minimization of repulsive forces between two nuclei by the cloud of shared electrons

What environment do chemical reactions in living systems occur in that requires a narrow range of temperature and pH?

an aqueous environment

When a proton is added to a water molecule, what ion forms?

hydronium ion

Calculation of pH

-log(base 10)[H+]

H+

indicates exact pH

OH-

represents the concentration of the pH subtracted from 14

Buffers are substances that help resist shifts in pH by

both donating H+ to a solution when bases are added and accepting H+ when acids are added

The monomers used by a cell as the building blocks for a polypeptide polymer are called

amino acids

What component assembles the selectively permeable boundaries around and inside cells?

fatty acids

What makes one amino acid different from another?

the different side chains (R groups) attached to an alpha carbon

What monosaccharide is required to synthesize nucleotide building blocks?

ribose

What holds to DNA double helix together?

hydrogen bonds

What is the relationship between dehydration reactions and hydrolysis reactions?

dehydration reactions assemble polymers and hydrolysis reactions break down polymers

What factor determines whether an interaction will be transient or stable

the surface complementarity between molecules

Magnesium

needed for DNA polymerase for replication

What DNA does Mitochondria contain?

maternal DNA

Magnification

the ratio of an object’s image size to its real size

Contrast

visible differences in parts of the sample

Nuclear Lamina

• Comprised of proteins to maintain the shape of the nucleus

• mutations here can cause progeria

First electron shell

holds 2 electrons

Second and Third electron shells

holds 8 electrons

Number of bonds needed for Carbon

4

Number of bonds needed for Nitrogen

3

Number of bonds needed for Oxygen

2

Molecular Shape

• determined by the positions of its atoms in valence orbitals

• determines the function of a molecule

• Hybridization can alter shape

Electronegativity Trend

Up and right on the periodic table

Saturated Fatty Acids

no double bonds

Unsaturated Fatty Acids

contains double bonds and kinks in structure