Unit 1 - Biochemistry in the Cell Flashcards
Distinctive Properties of Living Systems
- complicated and highly organized
- serve functional purposes
- actively engaged in energy transformations
- capacity for self-replication
Organisms capture energy in the form of?
special molecules
Organisms capture energy in the form of special molecules such as?
o ATP – Adenine Triphosphate
o NADPH – Nicotinamide Adenine Dinucleotide Phosphate
The Fidelity of Self-Replication Resides Ultimately in the Chemical Nature of?
DNA
DNA: Two complementary polynucleotide chains running in opposite directions can pair through _______ bonding between their __________ bases.
hydrogen
nitrogenous
DNA: Their complementary ___________ sequences give rise to structural complementarity.
nucleotide
Formation by e- pair sharing makes ___, ___, ___, and ___ appropriate for the support of life.
H, C, N, O
H, O, C and N make up ___% of atoms in the human body
99
What property unites H, O, C and N and renders these atoms so appropriate to the chemistry of life?
Their ability to form covalent bonds by electron-pair sharing
Hydrogen, Oxygen, Carbon, and Nitrogen percentage in the human body
Hydrogen: 63%
Oxygen: 25.5%
Carbon: 9.5%
Nitrogen: 1.4%
Units for Building Complex Structures
Simple Molecules
4 Simple molecules
o Metabolites
o Macromolecules and Membranes
o Organelles
o The Unit of Life is the Cell
Structural Organization of Complex Biomolecules
- inorganic precursors
- metabolites
- building blocks
- macromolecules
- supramolecular complexes
- organelles
- the cell
T/F:
Macromolecules and their building blocks have a “sense” or directionality and are informational.
True
Biomolecules have characteristic ______-dimensional architecture
three
______ forces maintain biological structure and determine biomolecular interactions
Weak
What builds proteins?
amino acids
What builds polysaccharides?
sugars
T/F:
Weak forces profoundly influence the structures and behavior of SELECTED biological molecules.
False
all biological molecules
Nucleic acids are polymers of?
nucleotides
hold atoms together so that molecules are formed
covalent bonds
T/F:
Weak forces create interactions that are CONSISTENT under physiological conditions
False;
constantly forming and breaking
Energies of weak forces range from _____ to ______
0.4 to 30 kJ/mol
Weak forces include?
- van der Waals interactions
- Hydrogen bonds
- Ionic interactions
mediated by weak chemical forces
Biomolecular recognition
Give the values of strength in kJ/mol
* Van der Waals Interactions:
* Hydrogen Bonds:
* Ionic Interactions:
* Hydrophobic Interactions:
- Van der Waals Interactions: 0.4-4.0 kJ/mol
- Hydrogen Bonds: 12-30 kJ/mol
- Ionic Interactions: 20 kJ/mol
- Hydrophobic Interactions: <40 kJ/mol
T/F:
Weak forces RESTRICT organisms to a narrow range of environmental conditions.
True
principle that guides the biomolecular interactions that characterize the living state
Molecular Recognition Through Structural Complementarity
A type of interaction where strength depends on the relative size of the atoms or molecules and the distance between them
Van der Waals interactions
A type of bond where the relative strength is proportional to the polarity of the bond donor and bond acceptor
Hydrogen bond
T/F:
In van der waals interactions, the size factor determines the area of contact between two molecules: the greater the area, the WEAKER the interaction.
False
stronger
T/F:
More polar atoms form stronger H bonds.
True
Type of interaction where strength also depends on the relative polarity of the interacting charged species
ionic interaction
T/F:
Ionic interactions cannot be H bonds.
False
Some ionic interactions are also H bonds: –NH3+ … -OOC-
Type of interaction where force is a complex phenomenon determined by a the degree to which the structure of water is disordered as discrete molecules or molecular regions coalesce
hydrophobic interactions
T/F:
Ionic bonds contribute to the stability of proteins.
True
Important to biomolecular interactions
Van der Waals Forces
Enhanced in molecules that are structurally complementary
Van der Waals Forces
surface protuberance on lysozyme recognized by the antigen-binding site of an antibody against lysozyme
Gin121
Process of life have durations ranging over ___ orders of magnitude
33
Plasma membrane of prokaryotic cells
single plasma membrane
Do prokaryotic cells contain nucleus?
No
Which is larger: prokaryotic cell or eukaryotic cell?
eukaryotic cell
(103-104 times larger)
Who designed a thousand DNA segments and combined them to make a synthetic version of the genome of Mycobacterium mycoides?
J. Craig Venter and colleagues
J. Craig Venter and colleagues designed a thousand DNA segments and combined them to make a synthetic version of the genome of?
Mycobacterium mycoides
What did mycobacterium mycoides produce?
self-replicating cells
What do self-replicating cells from mycobacterium mycoides represent?
the first artificial living organisms
a member of the coliform group of bacteria that colonize the intestinal tract of humans
escherichia coli
What structures can be found in prokaryotic cells?
cell wall
cell membrane
nuclear area or nucleoid
ribosomes
storage granules
cytosol
What structures can be found in animal cells?
extracellular matrix
cell or plasma membrane
nucleus
endoplasmic reticulum and ribosomes
golgi apparatus
mitochondria
lysosomes
peroxisomes
cytoskeleton
What structures can be found in plant cells?
cell wall
cell membrane
nucleus
endoplasmic reticulum
gogli apparatus
ribosomes
lysosomes
peroxisomes
cytoskeleton
chloroplasts
mitochondria
vacuole
cell wall (prokaryotic cell)
molecular composition:
function:
peptidoglycan;
mechanical support, protection
cell membrane
molecular composition:
function:
lipids and proteins;
permeable barrier that controls the entry of substances into the cell
nuclear area or nucleoid
molecular composition:
function:
single, tightly coiled, circular DNA molecule;
provides operating instructions for the cell
ribosomes
molecular composition:
function:
composed of small and large subunits;
site of protein synthesis
storage granules
molecular composition:
function:
storage forms of polymerized metabolites;
metabolic fuel
cytosol
molecular composition:
function:
gelatinous compartment;
site of intermediary metabolism
extracellular matrix
molecular composition:
function:
complex carbohydrates, proteins, and lipids;
cell-to-cell recognition, communication, cell adhesion, protective outer layer
nucleus
molecular composition:
function:
has a double membrane and nuclear envelope;
repository of genetic information encoded in DNA
rough endoplasmic reticulum
molecular composition:
function:
flattened sacs of internal membrane with ribosomes;
produce proteins
smooth endoplasmic reticulum
molecular composition:
function:
flattened sacs of internal membrane;
synthesizes lipids, phospholipids, and steroids
golgi apparatus
molecular composition:
function:
flattened membrane-bound vesicles;
packaging and processing of macromolecules
mitochondria
molecular composition:
function:
surrounded by two membranes;
site of ATP synthesis
lysosomes
molecular composition:
function:
contain hydrolytic enzymes;
intracellular digestion of materials entering the cell
peroxisomes
molecular composition:
function:
contain oxidative enzymes;
oxidize certain nutrients
cytoskeleton
molecular composition:
function:
protein filaments (actin);
shape of the cell, movement
cell wall (plant cell)
molecular composition:
function:
cellulose fibers in a polysaccharide/ protein matrix;
protection against osmotic or mechanical rupture
chloroplasts
molecular composition:
function:
double-membrane envelope, with stroma and lumen;
site of photosynthesis
vacuole
molecular composition:
function:
enclosed by tonoplast (single membrane);
transport and storage of nutrients and cellular waste products
genetic elements enclosed in a protein coat
viruses
Viruses are genetic elements enclosed in a?
protein coat
T/F:
Viruses are free-living organisms and can reproduce in other structures.
False;
not free-living, can reproduce only within cells
Viruses show an almost absolute __________ for their particular host cells, infecting and multiplying only within those cells.
specificity
