Flashcards in Chapter 1 Deck (68):
What are the three primary cells that feed of energy?
What is Organotrophic?
cells that feed on other organic molecules
What is phototrohic?
cells that feed on sunlight
What is lithotrophic?
Cells that feed on minerals from the earth
What type of cells are the most abundant form?
Organotrophic cells could not survive without either
What are aerobic lithothrophes?
Cells that use minerals for energy and atmospheric oxygen to drive the reactions
What are anaerobic lithotrophs?
Cells that use minerals for energy but do not use atmospheric oxygen to drive the reactions
What are the two basic classifications of cells?
Eukaryotes- membrane enclosed DNA
Prokaryotes- Non enclosed DNA
Name some characteristics of prokaryotes?
live as individuals
spherical, rod shaped
single cytoplasmic compartment
no organized internal structure
measure only a few microns
What are the main domains of life?
Which domains are prokaryotes?
What cause different species to arise?
How is the relation between different closely related species traced?
Some parts of the genome is mutates a lot. some parts of the genome is highly conserved.
How is all the life on earth related?
Through the ribosomal small subunit RNA is virtually the same in all living organisms
Why are prokaryotes small?
Small surface area to volume.
maximizes the cells uptake of nutrients across the plasma membrane increasing the cell reproductive rate
How many genes does a prokaryote have?
What is the genome size of prokaryotes?
10^6 - 10^7
What are the ways a new gene is created?
Horizontal (intracellular) Transfer
What is intragenic mutation?
Changes in DNA sequence by DNA replication
What is gene duplication?
a gene is duplicated within same cell
free to evolve on different paths
what is Segment shuffling?
Two or more gene segments join to form a new gene
What is Horizontal (intracellular) transfer?
Transfer of DNA from one genome to another even from different species
How does homologs arise?
When part of the genome is mistankely duplicated.
both genes are related but may or may not serve seperate functions.
What are homologs that derive from the same ancestral gene that are in two separate species and is similar in function?
What are homologs that derive from the same ancestral gene and are in the same species and diverged in function?
What type of cells readily has horizontal gene transfer?
prokaryotes- can result in cell picking up new traits
eukaryotes rarely have horizontal gene transfer
What cells are eukaryotes more similar in metabolic processes?
because of sexual mixing of early cells
What cells are eukaryotes more similar in infortion processing (DNA replication, transcription, translation).
because of sexual mixing of early cells
What is way to horizontal gene transfer?
only occurs between the same species
What is one characteristic of horizontal gene transfer?
they leave an individual more closely related relatives with respect some genes.
What can be deduced from the a gene sequence?
The function of a gene
How many gene families are conserved over all three domain?
What is the model organism studied by molecular biologist?
What are characteristics of E.coli that makes it ideal for study?
genetically differ from one to another
high rate of mutation
has fundamental mechanisms of life
Where do eukaryotic cells keep their DNA?
What is the nuclear envelope?
double layer membrane that separates the nucleus from the cytoplasm
What are some features of a eukaryote?
membrane enclosed organelles
10x bigger than prokaryotes
1000x larger volume
lack cell wall
What is one theory of the evolution of eukaryotic cells?
it was a predator cell,
requires large cell with flexible membrane and DNA to be in membrane away from the cytoskeleton
With what did primitive eukaryotic cells form a symbiotic relationship with?
Mitochondria wanted shelter for progeny
Eukaryotes wanted oxygen
What is mitochondria thought to be?
primitive oxygen metabolizing bacteria
What are some character of mitochondria?
Double plasma membrane
harness sugar to produce ATP
has its own ribosomes
has own tRNA
What are chloroplast?
similar to mitochondria they perform photosynthesis
mostly in plants
What does plant cells have that protects them?
Cell wall- prevents them from changing shapes
no phagocytoses and no movement
What do fungi posses?
Cell wall and mitochodria
since cant change shape because of the cell wall and have no chloroplast they are scavengers
Why are the genomes of eukaryotes hybrid?
DNA sequences move from the symbionts (Mitochondria, Chloroplasts) to the host cell.
Symbionts genome is a cutdown version of bacterial genome.
Why are eukaryotes genome so large?
1) larger predatory cells
2) transposable elements
Majority DNA is non-coding
What is the role that noncoding DNA play in the cell?
They are regulatory genes that regulate the expression of adjacent genes
this is needed for formation of more complicated organisms.
How does the cells differentiate in the body?
They are contain the same genes. regulatory genes control the differentiation of cells and their activity.
How do regulatory proteins control genome activity?
They bind directly or indirectly to regulatory DNA or interfere with the ability of other proteins to do so .
Most of coding genome codes for regulatory proteins
What are some unicellular eukaryotes?
What are characteristics Saccharomyces cerevisiae (single celled yeast) that makes it an ideal eukaryotoic cell to study?
Small single celled
closely related to plants and animals
easy to grow in nutrient medium
reproduce by cell division or sexually (by changing growth conditions)
what plant is the model plat for study?
What are the animals whose genome is sequenced?
What are the organisms that is not considered living?
Why are viruses not considered living?
cannot reproduce outside of host cell
What are viroids?
virus like entities that infect plant s
they are smaller than viruses and do not have a protein coat
What are the types of bacterial cell walls?
What are the parts common to both gram negative/positive cell walls?
peptidoglycan (thicker in gram positive)
What is in gram positive cell walls that is not in gram negative walls?
what is common to gram negative that is not common to gram positive cell walls?
Endotoxin/LPS (outer membrane)
What are the common shapes of bacteria?
rod shaped (bacilli)
What is the ribosomal large subunit of eukaryotes?
What is the ribosomal subunit of prokaryotes?
What are the cell wall made up of in eukaryotes?
cellulose or chitin
What type of E. Coli is used for labs?
E. Coli K12
what strain of E.Coli is pathogenic?
E.Coli 0157:H7 (EHEC)
What is the difference between K12 and )157:H7
0157 has 1.4 more DNA (5.5 MB versus 4.1)
1300-1600 more proteins than k12
131 is thought to be virulent
prophages may play an extra role in DNA