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105 Cards in this Set
- Front
- Back
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Cholesterol
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Polar amino acid
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Charged amino acid
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Steroids
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Structure:
contain 4 rings Ex: cholesterol -- (also an alcohol) cholesterol is a PRECURSOR for: -- steroid hormones -- bile -- vitamin D -- also found in the cell membrane |
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‘Fat-Soluble Vitamins’
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Include: vitamins D, E, and K
(C and the B vitamins are ‘water-soluble vitamins’) Used to make some coenzymes. |
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4 major classes of biomolecules
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carbohydrates
lipids proteins nucleic acids |
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Proteins
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built from AMINO ACIDS
20 different ones polypeptide contains many different a.a.s different ones have different sequences peptide bond a protein: one or more polypeptides, folded into a specific conformation |
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Protein Functions
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1) energy source/C source
2) storage 3) structural support 4) intercellular signaling 5) movement 6) transport 7) defense 8) ENZYMES |
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What TWO functional groups are found in EVERY amino acid?
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Amino Group and Carboxyl group
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THREE Groups of Amino Acids
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-Polar
-Nonpolar -Charged |
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Polypeptide Backbone
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-“−N−C−C” from each amino acid
-OXYGENS of −C ═ O -HYDROGENS of −NH -N and C termini |
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The order of nucleotides in a GENE determines....
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the order of amino acids in a protein, i.e. the primary structure.
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A protein folds in a precise way...
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based on its primary structure!
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Primary (1º) Structure
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results from covalent bonding between amino acids
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Secondary (2º) Structure
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characterized by localized protein folding
TWO types: 1) coils (alpha helices) 2) sheets (beta pleated sheets) results from h-bonding between backbone atoms (O and H) |
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Secondary (2º) Structure
a-helix |
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Secondary (2º) Structure b pleated sheet
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Tertiary (3º) Structure
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-overall 3-D structure formed by polypeptide
-involves R groups -hydrogen bonds -ionic bonds -van der Waals -hydrophobic -disulfide bridges |
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NONPOLAR AMINO ACIDS cluster in the interior of proteins.They interact with each other by....
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hydrophobic interactions.
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Two cysteines in a protein can become covalently bonded by a....
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A disulfide bond/bridge
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Cysteine Has ONLY a....
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Sulfhydryl Group
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Quaternary (4º) Structure
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hydrogen bonds
ionic bonds van der Waals hydrophobic |
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ATP Synthase has____ Subunits and weighs over ____ Daltons
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ATP Synthase has EIGHT Subunits, and weighs over 500,000 Daltons.
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All Proteins Have _____ or _____ Levels of Structure
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All Proteins Have THREE or FOUR Levels of Structure
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Folding occurs ___________, based on 1º structure
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Folding occurs SPONTANEOUSLY, based on 1º structure
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________ also affect the conformation.
1) 2) 3) Temperature |
Environmental factors also affect the conformation.
1)pH 2)[salt] 3)Temperature |
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Protein can be _______ and _______.
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Protein can be denatured and renatured.
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Nucleic Acids
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-nucleotides
-4 different ones polynucleotide -contains different nucleotides -different ones have different sequences -phosphodiester bond -two types -DNA and RNA |
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Nucleic Acid Functions
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information storage (genes)
-polynucleotides enzymes (Ch. 17) -polynucleotides molecular adaptor (Ch. 17 -polynucleotides energy source (Ex: ATP) -nucleotides cell signaling (“2nd messengers”) -nucleotides chemical rxns (Ex: coenzymes) nucleotides |
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nucleotide
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-a pentose sugar
-a phosphate -a nitrogenous base |
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Polynucleotide Backbone
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“−sugar−P” from each nucleotide
negatively charged! two different ends: 5' and 3' |
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Nuecleotide
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There are _____ chemically distinct nucleotides, that are used to build ___ and ___.
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There are EIGHT chemically distinct nucleotides, that are used to build DNA and RNA.
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The order of nucleotides in a _______ determines the order of amino acids in a protein, i.e. the primary structure.
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The order of nucleotides in a GENE determines the order of amino acids in a protein, i.e. the primary structure.
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Gene
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a unit of inheritance, consisting of a region of DNA.
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DNA is double-stretched
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-two polynucleotides wrap around each other.
-Hydrogen bonds |
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Pryimidimes
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Cytocine
Thymine Uracil |
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Purines
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Adenine
Guanine |
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Pyrimidine to Purtine Pairs
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G-C
A-T A-U T in DNA U in RNA |
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Prokaryotic cells
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DNA in nucleoid
no membrane-bound ~ 1-10 mm |
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Eukaryotic cells
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most DNA in nucleus
membrane-bound organelles ~ 10-100 mm |
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All Cells have...
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-- cell (plasma) membrane
-- contain cytosol (vs. cytoplasm) -- ribosomes -- 1000s of enzymes |
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What is the Composition of Cell Membrane?
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1) phospholipids
2) other lipids 3) diverse proteins |
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Where are the cells proteins?
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Everywhere
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What is a Ribosome?
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- 2 subunits
-made of 1/3 protein 2/3 RNA |
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system of membranes indirectly joined by _________.
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system of membranes indirectly joined by transport vesicles.
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ER consists of 2 parts
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RER (rough)
SER (Smooth) |
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R.E.R.
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covered with ribosomes
makes proteins! proteins can stay in E.R., OR leave travel to other parts of E.M.S. |
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Polypeptide is ________ Into ER
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Polypeptide is ‘Threaded’ Into ER
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S.E.R.
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no ribosomes
makes lipid detoxifies drugs stores glycogen |
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ER Makes ______ and ______.
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ER Makes Lipid and Protein
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Golgi Apparatus
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multiple flattened sacs
each contains a unique set of enzymes! receives, transmits, and buds off vesicles processes, then sorts and ships ER products |
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Where do Golgi vesicles go?
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to the cell membrane: secretion
to lysosomes… |
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Lysosomes are membrane-bound sacs of ________ __________.
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Lysosomes are membrane-bound sacs of hydrolytic enzymes
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EMS
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Synthesis, Modification and Breakdown of Biomolecules
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bound ribosomes makes proteins for the ______ and for _______!
1._____ 2._____ 3._____ 4._____ |
bound ribosomes makes proteins for the EMS and for SECRETION!
E.R. Golgi lysosome cell membrane |
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free ribosomes make proteins for:
________ _________ and _________ |
free ribosomes make proteins for:
cytosol, mitochondria and chloroplast |
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Mitochondria and Chloroplasts
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CONVERT ENERGY from one form to another
NOT PART of the EMS! they divide by ‘fission’ have their own DNA and ribosomes! they are SEMI-AUTONOMOUS |
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A Mitochondrion Uses ______
to Make _____. |
A Mitochondrion Uses Sugar
to Make ATP |
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A Chloroplast Uses _______
to Make ______. |
A Chloroplast Uses Light
to Make Sugar |
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Cytoskeleton
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--a network of fibers spanning the cytosol
-- gives the cell SHAPE/SUPPORT -- made of protein! -- provides MOTILITY, TRANSPORT -- dynamic (KEY ASPECT) |
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Cytoskeleton is Made of THREE Fibers
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1)Microfilaments
7 nm 2) Intermediate Filaments 8-12 nm 3) Microtubules 25 nm |
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Microfilament Functions
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create pseudopodia
cytoplasmic streaming muscle contraction animal cell division |
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Intermediate Filament Functions
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gives SHAPE/SUPPORT to the nucleus
main structural component of hair/nails and claws/horns/hooves |
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Microtubule Functions
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grow from the centrosome (near nucleus)
guide vesicle/organelle movement! cause flagella/cilia to beat cell division |
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Microtubules Form the ______ _______.
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Microtubules Form the Mitotic Spindle
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Motility/Transport Requires ______ _________.
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Motility/Transport Requires Motor Proteins
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Cell Walls
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found in plants, prokaryotes, fungi, and some protists
Functions: prevent cells from excessive water uptake gives support and form to multicellular orgs. |
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The cell membrane is both _________ AND _________.
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The cell membrane is both Hydrophilic AND Hydrophobic
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What holds bilayer together?
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hydrophobic interactions
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cell membrane is _____ thick , contains: other _______,
and has _______________ attached to it |
cell membrane is 7-8 nm thick , contains: other lipids,
and has oligosaccharides attached to it |
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Fluidity is ESSENTIAL for....
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-- for proper permeability
-- for functioning of membrane proteins |
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Factors Influencing Fluidity
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1) temperature
2) variations in the fatty acids -- single-celled organisms can alter # of double bonds! 3) cholesterol (animal cells) |
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Membranes are _______:
contains a __________ of proteins can be ______ OR ________ the __________ of a membrane protein determines its position in membrane proteins also have specific ________ |
embranes are MOSAICS:
contains a DIVERSE SET of proteins can be integral OR peripheral the 1º Structure of a membrane protein determines its position in membrane proteins also have specific ORIENTATION |
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Are unsaturated or saturated fats more fluid?
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unsaturated
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Types of membrane proteins
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1) transport
2) enzymatic activity 3) signal 4) cell-cell recognition 5) intercelluar joining 6) attachment to cytoskelton |
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Membranes are __________ _______.
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Membranes are selectively permeable
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permeability of a pure phospholipid bilayer
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- small, nonpolar molecules easily cross
- small polar molecules are partially blocked - large polar molecules are totally blocked - charged substances of ANY size are totally blocked |
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Permeability depends upon:
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1)permeability of a pure phospholipid bilayer
2)the presence of transport proteins |
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What CAUSES a substance to cross the cell membrane?
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diffusion: no energy input
—passive transport moving it across: energy input —active transport |
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A gradient has _________ _________.
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A gradient has POTENTIAL ENERGY.
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Two Types of Passive Membrane Transport
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small, nonpolar substances
Simple Diffusion polar and charged substances Facilitated Diffusion - two types: channels and carriers |
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Why Active Transport?
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moves substances AGAINST their gradients
requires INPUT of ENERGY uses a CARRIER proteins two types: 1° and 2° |
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1º Active Transport
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used to concentrate ions
via ion pumps driven by ATP |
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The Na+/K+ pump is ESSENTIAL for the ____________ of animal cells.
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The Na+/K+ pump is ESSENTIAL for the osmoregulation of animal cells.
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2º Active Transport
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involves the movement of TWO
substances: an ion and a molecule a.k.a. cotransport driven by the ion! |
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Transport by Vesicles
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macromolecules, particles, and small cells
two types: exocytosis endocytosis |
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Exocytosis equals?
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Secretion
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Some Types of Endocytosis
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phagocytosis
receptor-mediated endocytosis |
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Phagocytosis
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Allows eukaryotic cells to obtain “food” from the environment.
-- Ex: smaller cells -- relatively non-specific |
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Receptor-Mediated Endocytosis
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involves receptor proteins in the membrane
highly specific! allows cells to CONCENTRATE substances within them |
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RME Steps:
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LDL binds receptor.
Receptor diffuses to coated pit. Many receptors do the same. Coated pit becomes a coated vesicle. Vesicle fuses with lysosome. |
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What do cell junction proteins do?
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they join cells
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desmosomes
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join cells to tissues, and cell skeleton
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what makes the proteins found in the cell membrane?
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bound ribosomes
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what makes the proteins found in the cell membrane?
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bound ribosomes
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Metabolic Pathways
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anabolic
catabolic catabolism → anabolism |
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potential energy
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energy based on location OR structure
Ex: chemical |
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kinetic energy
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energy of motion
Ex: heat |
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Thermodynamics
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study of energy transformations.
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Laws of Thermodynamics
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First law: energy can only be TRANSFORMED.
Second law: disorder (S) of universe increases. CELLS MUST CONFORM TO BOTH! |
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Free Energy
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energy of system that can do work (at uniform
system temp) G = H – TS |
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anabolic
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build
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catabolism
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break down
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catabolism
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break down
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