DAT biology Flashcards
catabolic rxn
breakdown of complex molecules
anabolic rxn
synthesis of complex molecules
four main groups of organic compounds
carbohydrates, lipids, proteins and nucleic acids
carbs are source of ______
energy
forms of carbohydrates?
monosaccharides, disaccharides, and polysaccharides
what is monosaccharide
single unit of sugar, monomer, serves as building block for larger molecules
define disaccharide
two sugar units joined by glycosidic linkages
product of condensation
can be converted back to monosaccharide via hydrolysis
define polysaccharide
series of monosasccharides attached together by gloycosidic linkages
what is starch
polymer of glucose
used for storage in plants
two types: Amylose and amylopectin
difference between amylose and amylopectin
Amylose is a liner a-glucose polymer while amylopectin is a branched a-glucose polymer
glycogen
highly branched polymer of a-glucose
storage in animals
cellulose
linear B-glucose
used structurally in the walls of the plant
Chitin
polymer of nitrogen
attached B-glucose polymers
found in walls of fungi and exoskeletons of arthropods
examples of monosaccharides
fructose, glucose, Galactose
isomers of the CnH2nOn
Alpha vs Beta glucose
H and Oh are reversed on the first carbon
how many carbons is fructose and glucose compared to Ribose?
both are 6 whereas ribose is 5
what is condensation/dehydration
joining of two small molecules to make big one
what is hydrolysis
breakdown of bigger into smaller with the addition of water
Glucose +Fructose =?
Glucose +Glucose=?
Glucose +Galactose=?
sucrose
maltose
lactose
what kind of molecule are lipids
hydrophobic
functions of lipids
insulation
energy storage
structure
endocrine signaling
triglyceride/ triglycerol
glycerol backbone and 3 fatty acids
found in fats and oils
composition of triglycerol
glycerol: 3 carbons and 3 hydroxyl groups
fatty acids: hydrocarbon chains with COOH which makes it either saturated or unsaturated
saturated fats
single bonds
unsaturated fats
one/more double bond
can be cis or trans
could be mono or poly
cis unsaturated fats
hydrocarbon is kinky and prevents tight packing
trans unsaturated fats
no kinks
straight tails
mono unsaturated
one or more double bonds between 2 carbons
poly unsaturated
two or more double bonds
what makes up most of the plasma membrane?
phospholipids
what makes up the phospholipids
glycerol backbone
phosphate group
2 fatty acids
what is the R group attached to the phosphate
the R group on the phosphate varies since each serves a different function
phospholipids form a ______ ________, which is called____
lipid bilayer
cell membrane
Glycolipids composition
Glycerol backbone
carbohydrate( mono/oligo-saccharide)
2 fatty acids
where are the glycolipids found
on the outside surface of the plasma membrane
functions of glycolipids
varied functions…
are able to act as cell surface markers
Steroids composition
4 carbon ring backbone
what is cholesterol an example of and what is its function
example of a steroid
makes cell membrane more rigid and helps maintain structure
what is cholesterol a precursor to
vitamin D, bile and steroid hormones (testosterone and estrogen)
proteins
also called polypeptides
polymers of AA bonded covalently by peptide bonds
how many AA are there
20
Composition of Amino acid
amino group (NH2) carboxyl group(COOH) hydrogen R group(varies)
what happens when AA undergo condensation rxn
they form polypeptides with two different ends, namely N-terminus and C-terminus and also one molecule of water
N-terminus
end of polypeptide terminating with AA group of first AA
C-terminus
End of polypeptide terminating with AA group of last AA
Primary protein
Linear polymer of AA sequence
secondary protein
3-d shape of polymer because of hydrogen bonds between the amino and carboxyl groups of adjacent AA
two types of secondary proteins
alpha helices
Beta pleated sheets
secondary proteins structure is common in the_______
fibrous proteins
Most proteins have atleast _______ secondary structure
1
tertiary proteins
3d structure to further noncovalent interactions between AA R groups of secondary proteins which cause hydrophobic or hydrophilic regions
Name non covalent interactions
ionic bonds van der wals disulfide bonds hydrogen bonds Hydrophobic effects
tertiary proteins are common in ______
globular proteins
quaternary proteins
multiple polypeptide chains and hydrogen bonding forming complex structures
what is native state
structure of operative and functional protein
interaction above _______level(in protein) can be lost via denaturation
secondary
Denaturation
caused by pH and temperature changes
could also be a denaturing agent
sometimes change can be reversed but if the change is too much then reversibility may not be an option
Native state is encoded by the_______
primary protein structure
name different kinds of proteins
storage
transportation
enzymes
immunity
function of storage protein
stores AA
function of transport protein
vesicles that transport materials in and out of cells
function of immunity proteins
Protection against foreign particles
=Antibodies
function of enzyme protein
serve as catalysts and regulate rate change in a rxn
what are DNA and RNA composed of
nucleotides
what is a nucleoside
5 carbon sugar
nitrogenous base
nucleotide ?
5 carbon sugar(deoxy/ribose)
nitrogenous base
phosphate group
what determines if it is RNA or DNA
the 5 carbon sugar
more specifically if the OH at the 2’ carbon=ribose
if H at the 2’ carbon=deoxyribose
purines
Adenine and Guanine
2 ringed structure
pyrimidine
thymine/uracil and cytosine
1 ringed structure
what connects nucleotides?
phosphodiester bonds
5’ end
free phosphate group
3’ end
free hydroxyl group
how do phosphodiester bonds connect the nucleotides?
the phosphate of nucleotide A gets connected with the hydroxyl end of nucleotide B creating a backbone
DNA
right handed
antiparallel
double stranded helix
complimentary bases (DNA and RNA)
A-T/U= 2 hydrogen bonds G-C= 3 hydrogen bonds
RNA
single stranded nucleic acid synthesized from DNA
cell theory?(4points)
All living organisms are composed of one or more cells
Cells are basic unit of structure, function and organization in all organisms
All cells come from pre-existing living cells
Cells carry hereditary information
Central dogma of genetics
DNA->RNA->Protein
sometimes DNA can be converted into __ to function as ____
RNA
Ribozyme
what is a ribozyme
RNA molecule which can act as an enzyme
RNA world hypothesis
refers to the idea that self replicating RNA molecules are like precursors to current life
what can RNA do
store genetic info
catalyze chemical reactions
is RNA or DNA more stable? which is better for storing info?
DNA
DNA
endosymbiosis theory
mitochondria and chloroplasts were independent before but then were engulfed by larger cells to form the first eukaryotic cell
prokaryotic cells
unicellular organisms no membrane bound organelles nucleoid single chromosome/ plasmid Anaerobic or aerobic metabolism
tail like projections are for_____ ________________
cell movement
prokaryotic projections?
flagella (flagellin proteins)
eukaryotic projections?
flagella and cilia (tubulin subunits)
cilia arranged in a 9+2 fashion
Eukaryotic cells
uni/multicellular
membrane bound organelles
Large cells=larger ribosomes
Can be autotrophic or heterotrophic
DNA
long and tightly packed chromosomes with histone proteins
Autotrophic
primary producers
Able to synthesize complex molecules from simple compounds
Photoautotrophs
use light to synthesize carbohydrates via photosynthesis
Chemoautotrophs
Synthesize organic compounds form inorganic substances via chemosynthesis
Heterotroph
CONSUMERS
obtain energy from autotrophs or autotropic products
Obligate anaerobes
cant survive in oxygen
obligate aerobes
need oxygen for survival
facultative anaerobes
in the absence of oxygen can perform anaerobically
organelles
compartmentalized subunits enclosed by membrane
cytoplasm is made of ______
cytosol
Nucleus
contains DNA
Nuclear envelope
selectively permeable membrane of nucleus which has nuclear pores for regulation of traffic in and out of nucleus
composition of nuclear membrane
contains 2 phospholipid bilayers with perinuclear space
Nuclear lamina and its function
network of proteins under inner nuclear membrane
provides structural support
regulates mitosis
Nucleoplasm
fluid within the nucleus
nucleolus
region within nucleus where the assembly of both large and small ribosomes occurs
site for ribosomal synthesis
ribosomes
site for protein synthesis
encoded in mRNA proteins
free floating(synthesis of protein) and on ER(synthesis of secreted proteins)
rough ER
synthesis of protein designated for secretory pathway and plasma membrane
Smooth ER
synthesis of steroid hormones
detoxification of drugs and poison
in muscle cells stores Ca2+ for contraction
Golgi apparatus
receives vesicles from rough ER, modifies it and the encapsulated protein
directed to other regions for extracellular secretions
lysosomes
contain digestive enzymes that take part in intracellular digestion
Autophagy
the digestion of old cells by lysosomes
mitochondria
site of ATP synthesis and fatty acid catabolism via beta oxidation
contains its own circular DNA and ribosome
peroxisomes
detoxifying organelle which converts hydrogen peroxide into water using catalase
what are the specialized variations of the peroxisomes In the germinating plants called?
glyoxysome
Vacuoles
storage vesicles found in various types
transport vacuole
moves materials between and plasma membrane
food vacuole
merge with lysosomes which break down food
Storage vacuoles
plants store starch, pigments and toxic substances
Contractile vacuole
in unicellular organisms that collect and pump out water via active transport to prevent bursting
what kind of organisms have contractile vacuoles
organisms that live in hypotonic environments
Central vacuoles
found in plants
fill most of the interior to maintain turgidity
stores nutrients
carries out functions performed by lysosomes in the animal cells
name of specialized membrane in central vacuoles
tonoplast
Cell wall
supports the cell
found as cellulose in plants, chitin in fungi, peptidoglycan in bacteria, polysaccharides in some archea and protists
some have secondary wall under the primary one
extracellular matrix
fibrous structural proteins , adhesion proteins and other materials secreted by cells which fill space between the adjacent cells
function of ECM
provide mechanical support
help bind adjacent cells
proteoglycans
act as shock absorbing cushions between cells
collagen fibers
provide structural support to tissues
Adhesive proteins
create network by binding proteoglycans and collagen and to cell surface receptors
in what two ways do cells adhere to the ECM
FOCAL ADHESIONS -connection of ECM to actin filaments in the cell
HEMIDESMOSOMES- connection of ECM to the intermediate filament(ex. keratin)
Collagen
major component of ECM and is secreted by animal cells
Plastids
site of chemical synthesis and storage in plants, algae, and some eukaryotes.
undifferentiated plastids can become specialized
