Test 1 Review Questions Flashcards
what is an element
a substance that cannot be converted to simpler substance by ordinary chemical reactions
What components make up an atom?
nucleus, protons, neutrons, electrons
In what way do atoms differ from one another?
They have a different number of protons
How do protons and electrons relate to the chemical properties of atoms and molecules?
The protons determine what the atom is
it has the same number of electrons as it does protons
What is an ion?
an electrically charged particle
Why do ions form?
form when an atom gains or loses one or more elctrons
What happens when ions dissolve in water?
Their bonds are broken
What are the four categories of biologically important molecules?
Carbohydrates
Lipids
Polymers
Macromolecules
What elements are important for each category?
Carbohydrates - carbon, hydrogen, oxygen
Lipids - carbon and hydrogen
What are the basic functions for each category
Carbohydrates - store energy in chemical bonds
Lipids - long term energy storage
Polymers - single units, most biologically important molecules
Macromolecules - all ⬆️
What are some reasons simple molecules are formed into polymers
It makes them more complex
How are triglycerides composed
composed of 3 fatty acids
How are triglycerides and phospholipds similar and different
They both have fatty acids
Tri have three
Phospholipids have a phosphate group instead of glycerol
What does it mean to say glucose contains energy?
Contains bonds that can be broken to create energy
How is energy Released?
exergonic reactions
Three components of a nucleotode
phosphate
5-C sugar
Base
How are nucleotides joined together in a polymer
condensation reaction
Which nucleotide polymer is double stranded
DNA
Which nucleotides are complemetary
Why
A-T/U
G-C
A and G are Purines
and T, C and U are Pyrimidines
What are the three types of RNA
mRNA (messenger)
tRNA (transfer)
rRNA (ribosomal)
What are the components of all amino acids
Amino group Carboxyl group R side chain Hydrogen Carbon
Why is the similarity of amino acids important for the formation of peptide linkages
The amino acid and the Carboxyl group react together
What kind of bonds holds together protein structures?
Primary- peptide bonds
Secondary and tertiary - Hydrogen bonds
Why is protein shape so important?
Shape affects function
What effects do enzymes have on the energy barrier and reaction rate?
Enzymes make things happen faster
It lowers the energy barrier
What does it mean to denature a protein?
change it’s shape
it will no longer work
What factors cause a protein to denature?
Heat, alterations in concentration of H+ and high concentrations of polar substances
How do feedback loops allow cells to control their chemical processes?
They tell the cell if it needs more and should continue to make what it’s making or if it should stop
How do prokaryotes and eukaryotes differ?
Prokaryotes - no nucleus or membrane bound organelles
Eukaryotes- have a nucleus
What are the three domains of life?
Archea
Bacteria
Eukarya
What domain contains all multicellular life?
Eukaryotes
What does it mean for organelles to be membrane bound? How does it contribute to cell organization
It keeps things separate
What molecule forms the basis for biological membranes?
Phospholipids
What types of molecules are embedded in a membrane or attached to membranes
Carbohydrates
Proteins
What biological process depend on their membranes for their function and why?
Mitochondrion and chloroplast
How do membranes maintain differences between the space inside the membrane and the space outside?
the are selectively permeable
How can molecules cross membranes?
if the match the protein and and move through it
What does it mean to be gradient?
difference across the membrane
How do gradients relate to diffusion, osmosis, and active and passive transport
molecules move to where the concentration is lower to even it out.
What is meant by signal transduction pathway?
short and long term resononses
What starts the pathway?
a signal molecule connects with the recptor
What are the steps in the pathway
involves enzymes and proteins
What ends the pathway?
a cellular response
How do the steps along the way pass on the signal?
phosphorylation transmits the signal to thenext enzyme
kinase phophorylates the other molecules
