Bio 111 Lecture Exam 1

Are bacteria and archaea unicellular or multicellular?

unicellular

Are plants and animals unicellular or multicellular?

multicellular

Are protists and fungi unicellular or multicellular?

both

what can happen if cell division is uncontrolled?

cancer

is cell division typically controlled or uncontrolled?

controlled

What is the key element of life important for reproduction, growth, wound healing, and replacing cells that die or are lost?

cell division

what does cell division help with?

reproduction

growth

wound healing

replacing cells

what three things do all types of cell division need?

replication of genetic material

accurate segregation of genetic material

cytokinesis to divide the cytoplasm

what is cell division responsive to?

environmental conditions

are bacteria prokaryotes or eukaryotes?

prokaryotes

are plants, protists, and fungi prokaryotes or eukaryotes?

eukaryotes

are prokaryotic cells small or large?

small

do prokaryotic cells have a nucleus?

no, nucleus absent

do prokaryotic cells have membrane bound organelles?

no, they lack membrane-bound organelles

what shape are the chromosomes in prokaryotic cells?

circular

what process of cell division do prokaryotic cells do?

binary fission

are eukaryotic cells large or small?

large

do eukaryotic cells have a nucleus?

yes, nucleus present

do eukaryotic cells have membrane bound organelles?

yes, they have membrane bound organelles

what shape are the chromosomes in eukaryotic cells?

linear

what process of cell division do eukaryotic cells do?

mitosis/meiosis

what type of cells do binary fission?

prokaryotes

is binary fission a form of asexual or sexual reproduction?

asexual

where is genetic material during binary fission?

the nucleoid

what is the nucleoid?

a non membrane bound region of compacted DNA, contains proteins

do prokaryotes have more or less genetic material than eukaryotes?

less genetic material

how many chromosomes do prokaryotic cells usually contain?

one

how does all the dna fit into a cell?

it goes through compaction

what happens in the first level of prokaryotic DNA compaction?

the DNA loops around SMC proteins to form loop domains

what happens during the second level of prokaryotic DNA compaction?

the loop domains are further compacted into supercoils

what are the proteins that bind DNA in prokaryotes called?

SMC proteins

what is the first step in binary fission?

the cell increases in size

what is the second step in binary fission?

the circular bacterial chromosome is replicated

what is the last step In binary fission?

the two chromosomes are separated and segregated to opposite ends of the cell

where does replication of the chromosome in binary fission begin?

the origin of replication

where does replication of the chromosome in binary fission end?

the site of termination

which direction does replication proceed in binary fission?

both directions

what is septation?

dividing the cell into two

what is the role of FtsZ proteins in septation?

they form a Z-ring around the cell

what is formed as the z-ring shrinks in septation?

the septum

what are chromosomes?

large condensed molecules of DNA associated with proteins

what do chromosomes contain?

a particular set of genes

what is an uncondensed chromosome called?

chromatin

what is a centromere?

the middle of a chromosome, containing a repetitive DNA sequence

what are cohesin proteins?

they hold together sister chromatids after DNA replication

what are kinetochore proteins?

the site of microtubule/spindle attachment during cell division, on the outside of centromeres

what type of proteins are the inner part of centromeres?

cohesin proteins

what type of proteins are the outer part of centromeres?

kinetochore proteins

what are telomeres?

repetitive sequences of DNA that protect and stabilize the ends of chromosomes

what happens to telomeres when a cell divides?

they get shorter

what happens when telomeres get too short?

the cell can’t divide

what does telomerase do?

maintains telomere length

for how long does the body produce telomerase?

through embryonic development

when does telomerase reactivate?

in 90% of human cancers

about how much DNA does each human cell contain?

2 meters

what is a nucleosome?

the basic unit of chromatin,147 base pairs of DNA wrapped around 8 histone proteins

is the level of compaction consistent throughout a chromosome?

no, it varies

why is it important that the level of DNA compaction is dynamic?

it allows for gene expression

what is the name of the positively charged protein that helps bind DNA in eukaryotic compaction?

histones

what is a solenoid?

a section of tightly supercoiled DNA in between nucleosome and chromatin

what is the order of DNA compaction in eukaryotic cells from least compact to most compact?

DNA double helix, nucleosome, chromatin, solenoid, chromosome

are chromosomes more or less compacted during cell division?

more compacted

are chromosomes easier or harder to distinguish when they are compacted?

easier to distinguish

what are the five main phases of the eukaryotic cell cycle?

G1, S, G2, M, cytokinesis

what phases make up interphase?

G1, S, and G2

what is the period between nuclear divisions called?

interphase

what is it called when the cell is in a non-dividing state?

G0

what are the proteins that regulate the cell cycle called?

cyclins

what are cyclins?

regulatory proteins that accumulate and then dissipate within the cell in a specific pattern

without cyclins what would happen to the cell cycle?

it would stop progressing

what specific enzyme do cyclins regulate?

(cyclin dependent)kinases

what are kinases?

protein enzymes that phosphorylate other molecules

what does phosphorylate mean?

add a phosphate group to

what do phosphatases do?

dephosphorylate other molecules

what does getting phosphorylated do to a protein?

it affects the activity, either by location change or on/off switch, etc

what are the three amino acids that commonly get phosphorylated?

serine, threonine, and tyrosine

what are CDKs?

cyclin dependent kinases

are CDKs active or inactive when bound to a cyclin protein?

active

how are CDKs activated?

by being bound to a cyclin protein

do CDKs come and go throughout the cell cycle?

no, they are always there just not always active

do cyclins come and go throughout the cell cycle?

yes, they activate CDKs at certain times

what type of protein is needed to proceed through cell cycle checkpoints(CCCPS)?

cyclins

what are cell cycle checkpoints?

points at which the cell cycle can be stopped

what is the purpose of CCCPs?

they prevent cells from proceeding through the cell cycle when it’s not appropriate

whatare the three main CCCPs?

G1/S, G2/M, Spindle

what is the G1/S checkpoint committing to?

start or restriction checkpoint, the commitment to divide at all

what is the G1/S checkpoint regulated by?

cyclin/CDKs

what is the G2/M checkpoint committing to?

the commitment to proceed into mitosis or meiosis

what regulates the G2/M checkpoint?

cyclin/CDKs

what is the spindle checkpoint committing to?

commitment to proceed into anaphase

what regulates the spindle checkpoint?

anaphase promoting complex(APC)

what happens if a cell is unable to pass a CCCP?

cell division is halted and apoptosis may occur

what is needed to pass the G1/S checkpoint?

must be appropriate to divide, sufficient nutritional state of the cell, sufficient cell size, and no DNA damage

what is needed to pass the G2/M checkpoint?

all DNA must be replicated, sufficient cell size, and no DNA damage

what is needed to pass the spindle checkpoint?

chromosomes aligned properly and attached to a spindle

what are the most frequently mutated genes in all forms of cancer?

genes that control the cell cycle

what makes cancer cells difficult to treat?

they continue to divide inappropriately and accumulate mutations

what type of bond links the 5’ phosphate group to the sugar in a nucleotide?

phosphoester bond

what links nucleotides to each other?

the 3’ hydroxyl group

what type of bond is between two nucleotides?

phosphodiester bond