Flashcards in Bio Test #5 Deck (75):
What is the monomer for nucleic acids?
What is the polymer for nucleic acids?
DNA & RNA
What are the 3 main parts of the structure of Nucleotide?
a phosphate group
a nitrogenous base
Why are there different types of nucleotides?
Different type of nucleotides because different nitrogenous bases attached to them
What are the four different bases?
What group are the bases in?
Adenine & Guanine are Purines
Cytosine & Thymine are Pyrimidines
How are nucleotides linked together to create 1 strand?
Nucleotides are linked together by a covalent bond between the carbon in the 3rd position & the phosphate group
How many strands is DNA made of?
What keeps DNA strands together?
The strands are held together by hydrogen bonds between bases
What does complementary base pairing consist of?
Adenine only bonds with Thymine
Cytosine only bonds with Guanine
How many hydrogen bonds are needed for each complementary base pair?
Between Adenine & Thymine there are 2 hydrogen bonds
Between Cytosine & Guanine there are 3 hydrogen bonds
What are the functions of DNA?
DNA makes up our genes, it contains instructions to synthesize proteins for the whole, it transfers hereditary info from cell to cell
What are the functions of RNA?
makes mRNA (messenger), tRNA (transfer), rRNA (ribosomal)
copies & transports DNA instructions out of the nucleus (mRNA)
translates instructions into proteins (mRNA, tRNA, rRNA)
can also function as an enzyme
science that studies cells' structure and functions
person that studies cells
1. All organisms are made of cells & cells' products
2. Cells are the smallest & simplest, structural & function unit of life
3. Cells come from pre-existing
squamous, cuboidal, columnar, speroid, discoid, fusiform, fibrous
flat & angular; cover the esophagus, skin, lining of cavities, capillaries, alveoli
cube, liver cells
taller than wide, lining of intestine
roundish, fat cell
disk shape, red blood cell
thick in the middle & tapered at end, smooth muscles
thread like, skeletal muscle
a non-cellular structure composed of DNA/RNA and surrounded by a protein coat
What are characteristics of viruses?
Not cells made of the same material; have same genetic material
have the ability to evolve through natural selection
require a host to reproduce and survive
have an incubation period that varies according to virus
How important is incubation?
It is crucial to the virus spreading
What process does virus reproduction use?
How do viruses reproduce?
virus attaches to the host cell
virus injects its DNA/RNA into the cell
genetic material of the virus takes control of the host cell and tells the cell to make viral DNA/RNA and protein coats
viral DNA directs host cell to assemble viruses
new viruses destroy the membrane of the host cell and are released outside
What are prokaryotic cells?
Do not have nucleus, considered to be the most similar to a primordial cell
What do scientists believe about the first cell?
They believe that it was developed from non-living chemical substances. Even though this does not happen now and cells only originate from other cells
What are prokaryotes also called?
Prokaryotes are also called Bacteria
What are characteristics of prokaryotes?
They have few internal structures, but have a great variety of shapes & metabolic activity
What are 3 examples of Prokaryotes?
photosynthetic; make their own food using energy from sun; autotroph (self-feeding)
absorb N2 from atmosphere and transform it into nitrate (NO3) & nitrite (NO2) which are then used by plants
use decaying matter & through fermentation break it back into simpler nutrients, important in our digestive system
What are the 3 main shapes of Prokaryotes?
What is Gramstain and its significance?
a series of stains poured over a bacteria and
it indicates presence of certain chemicals in cell wall (purple if contains stain, pink if not)
How can bacteria be classified?
Through its shape, gramstain, and antibiotic resistance
How do you test bacteria's antibiotic resistance?
the bacteria is grown on plates with different kinds of antibiotics and if they grow that means they are resistant to that antibiotic
What are the functions for cell wall?
maintain shape, protect from others, and prevents cell from bursting
What are the functions for cell membrane?
separates inside of cell from outside environment, allows things in & out of the cell & regulates flow
What are the functions for mesosome?
involved in ATP production
What are the function for cytoplasm?
to contain enzymes for chemical reactions
What is the structure of cell wall?
Cell wall maintains modified sugar polymers called peptydeglygans
What is the structure of cell membrane?
made of phospholipids
What is the structure of mesosome?
made by foldings of the cell membrane
What is the structure of cytoplasm?
structure is a semi-transparent gelatinous
What are the functions for ribosomes?
synthesize protein by translating mRNA
What are the functions of Naked DNA?
store genetic info, transfer genetic info to daughter cells, directs all activities of the cell
What is the structure of ribosomes?
made of rRNA organized into 2 sub units; prokaryote cells have small ribosomes called "70s"
What is the structure of Naked DNA?
made of nucleotides and is organized in a loop
Describe other structures
their presence varies:
Pilus, Flagellum, Capsule, Endospore
an "other structure" there are 2 types
2. common pilus
stabilize bacteria during conjugation
attachment to surfaces, defense from phagocytic cells
long slender projection; its function is locomotion; can be either polar or peritrichus
moves in a whip like motion and propels cell forward
can have more than one strand on one side
can have more than one strand on multiple sides
hard covering; it protects
hard covering; function: survival in periods of environmental stress (changes in temp., pH, chemicals)
What are the 2 main processes of reproduction of bacteria?
Binary Fission & Bacterial Conjugation
asexual reproduction; not the same as mitosis
What are the advantages & disadvantages of Binary Fission?
Adv: it allows bacteria to grow rapidly
Dis: because all bacteria are identical, if something kills/harms one bacteria, it will affect the whole population
This process allows bacteria to grow exponentially
2 genetic material exchange between 2 already existing bacteria
extra chromosomal DNA, capable or replicating independently from the main DNA; can carry specific properties
What are considerations of Bacterial Conjugation?
This is how bacteria can acquire new properties that allow them to survive & evolve