Biology Review Book Flashcards
A child is diagnosed with an enzyme deficiency that prevents the production of hydrogen peroxide. What would likely be the outcome of such a deficiency?
peroxisomes are made of hydrogen peroxide and depend on it for function. The child will be unable to digest very long chain fatty acids… they would build up in the peroxisomes until displaced by other cell contents - ultimately result in cell death
aerotolerant anaerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
yes no yes yes
coronavirus is described as an enveloped, single-stranded positive-sense RNA virus. What does this indicate?
- the virus contains an outer layer of phospholipids with an inner capsid
- in the capsid there is a single stranded RNA that can be immediately translated to protein by the ribosomes of the host cell
describe conjugation mechanism of bacterial genetic recombination
the transfer of genetic material from one bacterium to another across a conjugation bridge
a plasmid can be transferred from F+ cells to F- cells OR a portion of the genome can be transferred from an Hfr cell to a recipient
Describe the pathway of retroviral nucleic acids from infection of host cell to release of viral progeny
- nucleic acid enters as single-stranded RNA
- RNA undergoes reverse transcription (using reverse transcriptase) to form a double-stranded DNA
- the DNA enters the host genome and replicates with the host cell
- the DNA is transcribed to mRNA which can be used to make structural proteins
- the mRNA doubles as the viral genome for new virions
- once new virions are assembled from the structural proteins and mRNA genome, they can be released to infect other cells
describe transduction mechanism of bacterial genetic recombination
the transfer of genetic material from one bacterium to another by bacteriophage
describe transformation mechanism of bacterial genetic recombination
the acquisition of exogenous genetic material that can be integrated into the bacterial genome
difference between cytoskeletal structures of centrioles and flagella
centrioles consist of 9 triplets of microtubules around a hollow center
flagella consist of 9 doublets on the outside and 2 microtubules on the inside
difference between lytic and lysogenic cycles?
lytic: bacteriophages replicate in the host cell in extremely high numbers until the host cell lyses and releases the virions
lysogenic: the bacteriophage genome enters the host genome and replicates with the host cell as a provirus; the provirus may leave the host genome and can be used to synthesize new virions
epithelial or connective tissue cells? alpha cells which produce glucagon in the pancreas
epithelial cells
epithelial or connective tissue cells? chondroblasts which produce cartilege
connective tissue cell
epithelial or connective tissue cells? endothelial cells which line blood vessels
epithelial cells
epithelial or connective tissue cells? fibroblasts which produce collagen in a number of organs
connective tissue cells
epithelial or connective tissue cells? osteoblasts which produce osteoid, the material that hardens into bone
connective tissue cell
facultative anaerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
yes yes yes yes
Golgi apparatus
vesicle brings product to it… it then packages and modifies it before sending it off in another vesicle
how do prions cause disease?
they trigger a change in the conformation of a protein from and alpha helix to a beta pleated sheet. this reduces the solubility of the protein and makes in highly resistant to degradation
how do eukaryotic and prokaryotic flagella differ?
eukaryotic flagella contain microtubules composed of tubulin organized in 9+2 arrangement
bacterial flagella are made of flagellin and consist of filament, a basal body, and a hook
in which ways are archaea similar to bacteria and eukaryotes
bacteria: single celled organism, no nucleus or membrane-bound organelles, have single circular chromosome, divide by binary fission or budding (prokaryotes)
eukaryotes: start translation with methionine, contain similar RNA polymerases, contain DNA associated with histones
list all parts of cell theory
- all living things are composed of cells
- cells are the basic functional unit of all living things
- all cells come only from preexisting cells
- cells carry genetic information (DNA) and pass it down
lysosome
break down cellular waste products and molecules ingested through endocytosis; can be involved in apoptosis
mitochondrion
generate ATP (produce energy for the cell’s functions); apoptosis
nucleus
stores genetic information; site of transcription
obligate aerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
yes
yes
no
no
obligate anaerobe (yes or no)
oxygen present: can survive? can carry out aerobic metabolism?
no oxygen: can survive? can carry out anaerobic metabolism?
no no yes yes
peroxisomes
break down very long fatty acid chains, synthesize lipids, contribute to pentose phosphate pathway
Rough ER
synthesizes proteins destined for secretion
smooth ER
produces lipids; detoxification
what are the 3 common shapes of bacteria?
spherical (cocci)
spiral (spirilli)
rod (basilli)
what are the 4 phases of the bacterial growth curve.. list their features
- lag phase - bacteria get used to environment; little growth
- exponential phase - bacteria use available resources ot mltipy at an exponential rate
- stationary phase - bacterial multiplication slows as resources are used up
- death phase - bacteria die as resources become insufficient to support the colony
What are the predominant proteins in microfilaments and its function
solid polymerized rods of ACTIN which makes the cell resistant to compression and fracture
what difference between the envelopes of gram-positive and gram-negative bacteria make gram-positive bacteria more susceptible to antibiotics such as penicillin?
Penicillin targets the enzyme that catalyzes the cross-linking of peptidoglycan.
Gram-positive bacteria have a thick layer of peptidolycan and lipoteichoic acid and have NO outer memberane
Gram-negative bacteria only have a thin layer of peptidoglycan but also have an outer membrane containing lipopolysaccharides and phospholipids.
Penicillin and antibiotics with similar function can more easily reach and weaken the peptidoglycan layer of gram-positive bacteria
What is the predominant protein in microtubules and what is a microtubule
it is a cytoskeleton structure composed of protein tubulin. it provides primary pathways for motor proteins (kinesin and dynein) to carry vesicles
- cilia and flagella movement of materials
what is the protein in intermediate filaments and what is an intermediate filament
lots of proteins and depends on what filament you have (keratin, desmin, vimentin, lamin)
deals with cell to cell adhesion and the maintenance of the integrity of the cytoskeleton… withstands a lot of tension
Why are viruses considered obligate intracellular parasites?
viruses don’t have ribosomes and organelles so in order for them to reproduce and synthesize proteins, they must infect cells and hijack their machinery
What are the 5 stages of the cell cycle? What happens in each stage?
G1 = cell grows and performs normal functions. DNA is examined and repaired S = DNA is replicated G2 = cell continues to grow and replicate organelles in preparation for mitosis; normal functions continue M = mitosis (cell division) G0 = the cell performs normal functions and is not preparing to divide
- G1/S checkpoint ensures DNA is in good condition
- G2/S checkpoint ensures organelles replicate and cell is appropriate size
p53 is the protein in control: when Tp53 gene is mutated the protein doesn’t work, and therefore the DNA is not checked = cancer
What are the 4 phases of mitoses, and what happens in each phase?
prophase = chromosomes condense, nuclear membrane dissolves, nucleoli disappear, centrioles migrate to opposite poles of cell and begin forming spindle apparatus metaphase = chromosomes gather along the metaphase plate in the middle of the cell under the guidance of the spindle apparatus anaphase = sister chromatids separate and a copy of each chromosome migrates to opposite sides telophase = chromosomes de-condense, nuclear membrane reforms, nucleoli reappear, spindle apparatus breaks down cytokinesis = cell splits into two identical daughters
What is the number and ploidy of the daughter cells produced from meiosis I? meiosis II?
meiosis I = 2 haploid daughter cells
meiosis II = up to 4 haploid daughter cells
What is the difference between homologous chromosomes and sister chromatids?
homologous chromosomes are related chromosomes of opposite parental origin (like having chromosome 15 from mom and chromosome 15 from dad).
sister chromatids are identical copies of the same DNA that are held together at the centromere.
After phase S, a cell contains 92 chromatids, 46 chromosomes, and 23 homologous pairs
For each phase of meiosis I what are the differences from the analogous phase of mitosis?
- Prophase I = homologous chromosomes come together as tetrads during synapsis; crossing over
- Metaphase I = homologous chromosomes line up on opposite sides of the metaphase plate, rather than individual chromosomes lining up on the metaphase plate
- Anaphase I = homologous chromosomes separate from eachother (centromeres do not break)
- telophase I = chromatin may or may not decondense; interkinesis occurs as the cell prepares for meiosis II
What are the 4 functions of the interstitial cells of Leydig and Sertoli cells?
interstitial cells of Leydig: secrete testosterone and other male sex hormones (androgens)
sertoli cells: nourish sperm during development