Exam 2 Flashcards
What are proteins?
macromolecules that perform majority of cell’s function
What are amino acids?
monomers of proteins
How many amino acid groups are there?
20 different side groups and 20 different amino acids
What types of side groups are there for amino acids
Nonpolar (hydrophobic, no oxygen) polar (hydrophilic) charged (hydrophilic)
What forms dipeptides
2 amino acids linked together
What is a peptide bond?
Bond holding amino acids together within dipeptide
What is a polypeptide
long polymer chains formed by linking hundreds of amino acid monomers
What are the 4 levels of protein structure?
Primary, secondary, tertiary, quaternary
What is primary structure?
polypeptides’ linear sequence of amino acids
What is secondary structure?
local patterns formed in polypeptide chains
What is tertiary structure?
entire polypeptide chain folded into its functional conformation
What is the tertiary structure reinforced by
Hydrogen bonds, ionic bonds, disulfide bridges, van der Waals interactions.
What are fibrous proteins?
Structural proteins
What are globular proteins?
enzymes and other proteins
What is quaternary structure?
when proteins consists of 2 or more polypeptide chains
What can alter tertiary structure?
extreme of temp, pH, salinity or other environmental factors will lead to protein denaturing.
What determines primary structure?
Nucleic acids
What are nucleic acids?
inherited information that functions as a cell’s genetic material
Examples of nucleic acids?
DNA, RNA
What do nucleic acids do?
Store instructions for protein synthesis
What does DNA do?
serve as temple for synthesizing RNA- transcription
What does RNA do?
Serve as template for synthesizing proteins- translation
What are nucleotides held together with?
Nucleic acids by phosphodiester linkages
RNA nucleotides 3 components?
Sugar (deoxyribose) phosphate group (negatively charged) one of 4 possible nitrogenous bases (adenine, cytosine, guanine, Uracil)
DNA nucleotides 3 components?
Sugar (deoxyribose) phosphate group (negatively charged) one of 4 possible nitrogenous bases (adenine, cytosine, guanine, thymine)
Example of nitrogenous base single-ring?
Cytosine, thymine, uracil
Example of nitrogenous base double-ring?
Adenine, guanine
DNA consists of what?
2 nucleic acid strands coiled around each other
RNA consists of what?
Single nucleic acid strand
What is cell theory?
Cell is the fundamental unit of life
What is a light microscope?
beam of light is passed thru specimens for living cells to be observed.
What is a scanning electron microscope?
beam of electrons is passed thru specimen, cells must be dead for details of cell’s outer surface
What is Transmission electron microscope?
cells must be dead, with beam of electrons used for cell’s internal structure
Why are cells so small?
As cell size increases surface area-to-volume ratio decreases
What are all organisms possessing prokaryotic cells?
Unicellular
Prokaryotic cells lack what?
Nucleus and other membrane- enclosed organelles
What is the nucleoid region?
region of cell where DNA is located
What do ribosomes do?
Synthesize proteins using info stored in DNA
What does plasma membrane do?
Regulates transport of materials into and out of the cell
What does the cell wall do?
Provides structural support
What do capsules do?
Provide protections
What does pili do?
Allow bacteria to attach to surfaces
What does the flagella do?
Enable movement
Most organisms possessing Eukaryotic cells are?
Multicellular
Examples of multicellular eukaryotes?
Animals, plants, fungi and some protists
What do eukaryotic cells possess?
Nucleus and other membrane-enclosed organelles
Organelles found in animal cells but not plant cells?
Centrioles, lysosomes, flagella and cilia
Organelles found in plant cells but not animal cells?
Cell wall, chloroplasts, cell wall with plasmodesmata
2 major Plasma membrane molecules?
Phospholipids and proteins
What do short carbohydrate chains attached to phospholipids form?
Glycolipids or glycoproteins
Plasma membrane phospholipids contain?
Hydrophobic tail (2 fatty acids) hydrophobic head (phosphate group)
What do plasma membranes exist as?
Phospholipid bilayers
Peripheral proteins attach to what?
Either the inside or outside of the membrane
Integral proteins span across what?
The entire membrane from the inside to the outside of the cell
The Nucleus is the cell’s what?
Control center
What is the structure of the nucleus?
Nuclear envelope, DNA, nucleolus
Function of nucleus?
Ribosomes are manufacturer in nucleolus, translation, transcription
Ribosomes function where?
Protein synthesis
Cytoplasm includes what?
All of cell inside plasma membrane and outside the nucleus
What is the endomembrane system?
Many organelles surrounded and connected to each other by membranes
Endoplasmic reticulum is what?
A manufacturing organelle
What are many attached ribosomes called?
Rough ER