Bio MT1 Flashcards
What is adhesion
The clinging of one substance to another
Why is water able to absorb or releases large amts of heat with only slight change in its own temp
H2Os high specific heat
In isomers, why is structure important
Structure = function
Enatiomers
Mirror image isomers
Cis-trans isomers
Cis isomer: the two molecules are on the same side
Trans isomer: the two molecules are on opposite sides
Hydroxyl group
—OH, alcohols, polar, can form H-bonds
Carbonyl group
C=O, found in sugars
Carboxyl group
OH-C=O, acidic properties
Amino group
-NH2, acts as a base; picks up an extra H+
Sulfhydryl
-SH
Phosphate group
OPO3
Methyl
-CH3
What synthesizes a polymer
Dehydration reaction— H2O formed from short polymer and unlinked monomer
Hydrolysis
Breaks down a polymer— adds water molecule
Enzymatic proteins function
Selective accelerations of chemical reactions
Defensive proteins
Protection against disease
Storage proteins
Store amino acids, ex) antibodies inactivate and help destroy viruses and bacteria
Transport proteins
Transport of substances ex) hemoglobin, the iron-containing protein of vertebrae blood, transports oxygen from the lungs to other parts of the body. Other proteins transport molecules across cell membranes
Hormonal proteins
Coordination of an organism’s activities
Ex) insulin
Receptor proteins
Response of cell to chemical stimuli
Contractile and motor protins
Movement
Ex) motor proteins are responsible for the undulations of cilia and flagella; actin and myosin proteins are responsible for the contraction of muscles
Structural proteins
Support
Ex) karat in, collagen, and elastin
Building blocks of proteins— monomers
Amino acids
Why are the 9 essential amino acids essential?
You have to ingest them— our bodies can’t make them
Polypeptide
Polymer constructed from amino acids— just a chain— not folded yet
What is at the N-terminus of an amino acid
Amino group— NH3
What is at the C-terminus of an amino acid
Carboxyl group
What are amino acids joined by
Peptide bond
What is the number of molecules needed to completely hydrolyze a polymer
N-1
What is at the beginning of an amino acid chain
N-terminus
Primary protein structure
Chain of amino acidsq
Secondary protein structure
Hydrogen bonds between amino and carbonyl groups in backbone— alpha helix and beta sheet
Tertiary structure of a protein
Interactions between R groups
Quaternary structure of a protein
Aggregation of multiple polypeptides
What are DNA and RNA monomers called
Nucleotides
Nucleotide 3 parts
Nitrogenous base, 5-carbon sugar, phosphate group
What is the phosphate group in RNA
Ribose
What is the phosphate group in DNA
Deoxyribose
In the 5- carbon sugar, where is the phosphate group bonded and where the nitrogenous base bonded
Phosphate: 5’ carbon
Nitrogenous: 1’ carbon
In the middle is an oxygen
What forms the phosphodestier linkages between sugar and phosphate components of backbone
Condensation rxns
Where is energy supplied for nucleotide polymerization
Activated nucleotides: (NTPs and dNTPs)
Chargaffs rules
Amt of A=T and C=G
First person to publish DNA structure (it was wrong)
Linus Pauling
Who published paper on DNA structure
Watson and Crick
Who took photo of helix DNA
Rosalind Franklin
Who showed Watson and Crick Franklin’s helix photo
Maurice Wilkins
What are opposite DNA strands held together by
H-bonds
Adenine always pairs with _____ in DNA
Thymine
Guanine always pairs with ______in DNA
Cytosine
Difference between ribose and DNA
Has an extra OH, makes it more unstable
What does A bond with in RNA
U
RNA is usually ______ stranded
Single
RNA functions
Protein synthesis, gene expression, catalyze rxns, genetic material
Oligosaccharides
Oligo=few, little
Carbs
Most common monosaccharide
Glucose
Simple sugars
Monosaccharides
Most monosaccharides have chemical formulas that are some multiple of what
CH2O
Different ways monosaccharides are classified
Location of carbonyl group, length of carbon skeleton, arrangement around asymmetric carbons
Disaccharides’ covalent bond
Glycosidic linkage
What reaction synthesizes polysaccharides
Dehydration rxn
Common disaccharides
Sucrose, lactose, maltose
2 general purposes for polysaccharides
Storage and structure
Storage polysaccharides
Starch, glycogen
Structural polysaccharides
Chitin, peptidoglycan, cellulose
What forms the cell wall of fungi and exoskeleton of insects and crustaceans
Chitin (is a carb)
What makes up the cell wall of bacteria and contains amino acids
Peptidoglycan (is a carb)
What is a component of plant cell walls
Cellulose (carb)
Main functions of carbohydrates
- Provide carbon skeletons for more complex molecules
- Structural support
- Energy storage (photosynthesis/ Glucose used to make ATP)
What is necessary for cell-cell recognition and how the body recognizes foreign invaders
Carbohydrates
How do lipids interact with water
Hydrophobic
How are steroids characterized
By a carbon skeleton with four fused rings; distinguished by the different chemical groups attached to the rings
What is cholesterol
A steroid (a fat)
Cholestrerol
Important component of cell membranes, precursor from which other steroids are synthesized such as sex hormones
Cholesterol that clogs arteries
LDL
Cholesterol that removes the other cholesterol from bloodstream
HDL
Fats are not actually a polymer
True
What two smaller molecules are fats constructed from
Glycerol and fatty acid
How do fatty acids and glycerols attach
Dehydration reaction leads to ester linkage
No double bonds — what kind of fat
Saturated fat— saturate with hydrogen
One or more double bonds— what kind of fat
Unsaturated fat
What causes bending in an unsaturated fat
Cis double bond
Types of fats that are solid at room temp
Saturated
Types of fats that are liquid at room temp
Unsaturated
Trans fat
Unsaturated + hydrogen = straight molecule that is man made— made bc shelf-stable
Phospholipids contain waht
Hydrophilic head, hydrophobic tails (fatty acids)
Amphipathic meaning
Has both hydrophobic and hydrophilic partsw
What is the plasma membrane made up of
Phospholipids— fatty acids of different lengths and saturation influence membrane permeability
Two major types of membrane proteins
Integral and peripheral
Protein that spans the membrane with segments both inside and outside the cell, needs to be both hydrophobic and hydrophilic
Integral (transmembrane)
Protein that is loosely bound to the surface of membrane
Peripheral — often interact with exposed surface of integral proteins
Functions of membrane proteins
- Transport
- Enzymatic activity
- Signal transduction
- Cell-cell regocnition
- Intercellular joining
- Attachment to the cytoskeleton and extracellular matrix
What can easily make it through the selectively permeable membrane
Small non polar molecules
What molecules are impeded by the hydrophobic interior o the membrane
Ions and polar molecules
Movemembnt across the membrane that requires no energy
Facilitated diffusion: passive transport
Active transport
Requires energy to move molecules
Passive transport includes movement of any molecule _______ its concentration gradient
Down
Diffusion is a type of
Passive transport
Diffusion is spontaneous
True
Diffusion of water across a semipermeable membrane
Osmosis
Isotonic
Environment same as the cell
Hypertonic
More solutes in the environment
Hypotonic
Less solutes in the environment
What helps the diffusion of polar molecules and ions
Transport proteins
What do channel proteins do
Provide doorway through membrane
What do carrier proteins do
Change shape to shuttle the molecule across the membrane
Ion pumps
Used in active transport: need energy: crucial for maintaining the electrochemical gradients and membrane potential for nerve impulses
Secondary active transport (cotransport)
Uses the concentration gradient created by an ATP-powered pump to power the transport of a molecule against its own concentration gradient
What types of organisms are prokaryotes
Bacteria and archaea
Prokaryotes have:
NO defined nucleus (nucleoid)
DO have ribosomes, plasma membrane, organelles
What control entry and exit from the nuclear membrane
Nuclear pores
What maintains the shape fo the nucleus
Nuclear lamina
What does the nucleolus do
Synthesis of rRNA and assembly of ribosome subunits
What do ribosomes do
Carry out protein synthesis
What are ribosomes made of
RNA and proteins
Free ribosomes
Make proteins which will function in the cytosol
Bound ribosomes
Make proteins which will be inserted into membranes or secreted
Cells with high rates of protein synthesis have a lot of what
Ribosomes
Ribosomes are not surrounded by membranes so they are technically not what
Organelles
What are in the endomembrane system
Endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles
Where are bound ribosomes bound to
Endoplasmic reticulum
What functions does the endomembrane system carry out
Protein synthesis, transport, metabolism, synthesis of lipids, detox of poisons
Why is the smooth ER smooth
Lacks ribosomes
What is the ER continuous with
Plasma membrane
What are the functions of the smooth ER
Lipid processing, storage of calcium ions, detox of drugs and poisons
rough ER functions
Proteins destined for secretion, shipped to other organelles or embedded in the membrane
What does the Golgi apparatus do
Modifies, stores, and ships proteins
Receiving side of golgi apparatus
Cis face
Shipping side of Golgi apparatus
Trans face
Organelle that is stacks of membranous sacs and not physically connected
Golgi apparatus
What are Golgi apparatus products transported by
Vesicles
Membranous sac of enzymes that digest macromolecules
Lysosomes
Phagocytosis
Engulfing solid particles and breaking them down
Autophagy
Recycles the cell’s own organic material, done by lysosomes
Lysosomes’ enzymes function best under ______ condition
Acidic
What do vacuoles do
Storage: reserves of important organic compounds, poisonous compounds, pigments
+ central vacuole in plants
what does the central vacuole in plants do
Stores inorganic ions
Allows cells to grow large without increasing cytoplasm
Help plant remain rigid
Peroxisomes
Centers for redox rxns, often produce h2o2, breakdown fatty acids, detoxify alcohol and other toxic cmpds
Most likely pathway that will be taken by a newly synthesized protein that will be secreted by the cell
Rough ER -> Golgi -> vesicles that will fuse with the plasma membrane
Mitochondria is found in what type of cell
Eukaryotic cell
Mitochondria membrane
Double membrane: smooth outer membrane and inner membrane has lots of folding, which increases SA
Mitochondria contain their own what
DNA and ribosomes
Site of cellular respiration
Mitochondria
Chloroplasts
Double membrane, contain their own DNA and ribosomes, contain chlorophyll, site of photosynthesis
Nuclear transport
Highly regulated, proteins destined for the nucleus have specific amino acid sequence (nuclear localization sequence or nuclear export sequence)
ALL protein synthesis starts on ____ ribosomes
Free
Proteins meant for endomembrane system or secretion are marked by a what
Signal peptide
What escorts the ribosome to the ER membrane
Signal recognition particle
Growing polypeptide snakes across membrane into ER what
Lumen
Proteins are secreted through what
Exocytosis (bulk transport)
Large molecules are brought into the cell through
Endocytosis
Pinocytosis
Cell drinking (liquids)
Large molecules that are brought into the cell are digested by what
Lysosomes— the building blocks are recycled
3 main cytoskeleton fibers
Microtubules, microfilaments (actin), intermediate filaments
Microfilaments — function
Functions:
Maintenance of cell shape, changes in cell shape, muscle contraction, cell motility, cell division (cleavage furrow formation)
Intermediate filaments - function
Functions:
Maintenance of cell shape, anchorage of nucleus and certain other organelles,
Formation of nuclear lamina
What do nuclear lamina do
Help maintain nucleus shape
Smallest cytoskeleton fibers
a microfilaments (7nm)
What are microtubuoles made of
Tubulin
Function of microtubules
Maintenance of cell shape, cell motility (as in cilia or flagella), chromosome movements in cell division, organelle movement
Think of the little vesicles walking on top of the microtubule
What are intermediate filaments made of
Made of fibrous proteins supercooled into thicker cables— several different proteins
What are microfilaments made of
Actin— two intertwined strands of actin, each a polymer of actin subunits
catabolic reactions
breakdown complex molecules and RELEASE energy
anabolic reactions
use energy to build complex molecules
2nd law of thermodynamics
every energy transformation or transfer increases the entropy of the universe
exergonic reaction
reaction is spontaneous: energy is released
endergonic reaction
reaction is nonspontaneous, energy is added
energy coupling
use of exergonic reactions to drive endergonic reactions– usually happens thorugh transfer of electrons or phosphate group
oxidation
loss of electrons
why does the partial negative charge in a molecule of water occur
the electrons shared between the o and h atoms spend more time around the O atom nucleus than around the H atom nucleus
what group plays a major role in energy transfer
phosphate group
which of the following is not attached to the central C atom in an amino acid?
carboxyl functional group
oxygen
amino functional group
side chain (“R group”)
oxygen
what part of an amino acid is always acidic
carboxyl functional group
how do polypeptides from amino acids form
a bond forms between the carboxyl functional group of one amino acid and the amino functional group of the other amino acid
what type of bond joins the monomers in a proteins primary structure
peptide bonds
what bonds do the secondary structure of a protein result from
hydrogen bonds
what are the tertiary structures of a protein DIRECTLY dependent on
hydrophobic interactions, ionic bonds, bonds between sulfur atoms, hydrogen bonds
what do cells do to activate the nucleotides for incorportation into a polymer and why
add phosphate groups to raise the potential energy of monomers
in the 1950s when Watson and Crick were working on their model of DNA, which concepts were well-accepted by the scientific community
- chromosomes are made up of protein and nucleic acids
- genes are located on chromosomes
- chromosomes are found in the nucleus
what did the structure of DNAs double helix suggest about dnas properties
dna can be replecated by making complementary copies of each strand
dna can change. errors in copying can result in changes in the dna sequence that could be inherited by future generations
dna stores genetic info in the sequence of its bases
hydroxyl groups in nucleic acid: on 3’ or 5’ carbon
3’
phosphate groups in nucleic acid: on 3’ or 5’ carbon
5’
what do animals store energy in the form of
glycogen
most abundant organic cmpd on earth
cellulose
glycosidic linkage is analogous to what in proteins
peptide bodn
how do polysaccharides vary
monomers vary in orientations of hydroxyl groups, linkages vary widely in location and geometry
a function of cholesterol that does not harm health is its role
as a component of animal cell membranes
the presence of many C-C and C-H bonds causes fats to be …
rich in energy (can be oxidized) and insoluble in water
heads of triglycerides are derived from what
glycerol
in the rxn that builds a fat, ______ groups react with ______ groups
hydroxyl (come from glycerol), carboxyl
triglycerides vary with respect to the number of
C atoms in the tails and double bonds in the tails
what do DNA< proteins, and fats have in common
they contain carbonyl groups
decreasing the saturation of the fatty acid chains on a particular type of phospholipid would result in the formation of what
more fluid bilayers
what is composed of DNA and protein
chromatin
ribosomal subunits are manufactured by what
nucleolus
hollow rods that shape and support the cell
microtubules
what are identical in structure to centrioles
basal bodies
where are proteins produced other than on ribosomes free in the cytosol or ribosomes attached to the ER
mitochondria
sacs in chloroplasts
thylakoids
fluid that surrounds thylakoids in chloroplasts
stroma
what is the function of a bacteriums capsule
protection
what are the surface appendages that allow a bacterium to stick to a surface
fimbriae
in eukaryotic flagella, the fibers that slide past one another due to the activity of dynein proteins are what
microtubules
many cell organelles, most notably the nucleus, are anchored by ________ wgucg are assembled from a diverse class of proteins
intermediate filaments
centrosomes are sites where protein dimers assemble into what
microtubules
the extension of pseudopodia in amoeba is due to the regulated assembly and destruction of what
microfilaments
the only cytoskeletal fibers not associated with intracellular movement or whole cell locomotion are what
intermediate fibers
during muscle contractions, mytosin motor proteins move across tracks of what
microfilaments
why does water have a high specific heat
hydrogen bonds
an animal lacking oligosaccharides on the external surface of its plasma membrane would likely be impaired in which function
cell-cell recognition
______ fatty acids and ____ hydrocarbon chains increase membrane permeability
unsaturated; short
which of the following (polysaccharides, RNA, proteins, DNA) have the least structural variety
DNA
do plant cells contain mitochondria
yes
