MODULE 1 (PPT) Flashcards
is the smallest unit of living things.
cell
The basic building blocks of all organisms
cell
The Cell Theory (3)
The cell is the fundamental unit of structure and function in all living things.
All organisms are made up of one or more cells.
Cells are from other cells through cellular division.
The cell theory expanded version (3)
Cells carry genetic material passed to daughter cells during cellular division.
All cells are essentially the same in chemical composition.
Energy flow (metabolism and biochemistry) occurs within cells.
Different Cell Types (2)
Prokaryotes
Eukaryotes
organisms belonging to the domains Bacteria and Archaea.
Prokaryotes
includes protists, fungi, animals, plants
Eukaryotes
Prokaryotic cells – do not possess a true _________, i.e., their DNA is not confined within the nuclear _____________.
nucleus,
membrane
➢No sub-cellular organelles like mitochondria, Golgi bodies, or endoplasmic reticulum
Prokaryotic cells
Eukaryotic cells are made of functional subcellular
compartments – a true _________ and various membrane-bound _________.
nucleus,
organelles
The genetic material within the nucleus is complex. The DNA is associated with histone proteins and thus, called _______.
chromosomes
Eukaryotic cells vary depending on the nature of eukaryotic organisms. E.g. cells in a leaf contain _______
chloroplast
What do all cells share in common? (4)
- Cell membrane
- Cytoplasm
- Ribosomes
- DNA (and RNA)
Houses water and minerals, proteins, and organelles
Cytoplasm
Common features of all cells (5)
- Universal Genetic Code
- The same 20 amino acids
- Universally conserved genes
- Making proteins
- Chemiosmosis
- Metabolic pathways
All cells make most of their ATP using the same process (______) using: _______ (3)
Chemiosmosis,
Membranes
Proton gradients/ proton motive force
ATP synthase
is the biological medium here on Earth and is the most abundant substance in living systems
water
water make up ____% or more of the weight of most organisms.
70%
is the only common substance to exist in the natural environment in all three physical states of matter.
Acknowledging that life adapts to its environment through natural selection, ______ emphasized that for life to exist at all , the environment must first be suitable and that leads to water.
water;
Henderson
Water has four emergent properties such as
- Cohesion and adhesion of water molecules
- Moderation of temperature
- Evaporative cooling of water
- Water as the solvent of life
biomolecules (4)
- lipids
- nucleic acid
- carbohydrates
- proteins
Nucleic acids are macromolecules that exist as polymers called __________ (consisting of monomers called ________)
polynucleotides
nucleotides
A nucleotide is composed of three parts:
a nitrogenous
base, a five-carbon sugar, and
one or more phosphate groups.
The portion of the nucleotide without any phosphate groups is called a _________
nucleoside
is a biologically functional molecule that consists of
one or more polypeptides (polymers of amino acids), each folded and coiled into a specific
three-dimensional structure
proteins
Many proteins are roughly spherical (________),
while others are shaped like long fibers (________)
globular proteins;
fibrous proteins
Folding of proteins are done by
chaperonins
when proteins are transferred from an aqueous environment to a nonpolar solvent, it unravels and loses its native shape by a process called ________
denaturation
Structures of Proteins (4)
primary
secondary
tertiary
quaternary
It is a linked series of amino acids with a unique sequence.
is determined not by the random linking of amino acids, but by inherited genetic information.
primary structure
This is collectively referred to as coils and folds, which are the result of hydrogen bonds between the repeating constituents of the polypeptide backbone.
Secondary structure
a delicate coil held together by hydrogen bonding between every fourth amino acid.
a- helix
two or more strands of the polypeptide chain lying side by side (called b strands) are connected by hydrogen bonds between parts of the two parallel polypeptide backbones
b pleated sheet
It is the overall shape of a polypeptide resulting from interactions between the side chains (R groups) of the various amino acids.
Tertiary structure
It is the overall protein structure that results from the aggregation of these polypeptide subunits, ____________ (2)
quaternary structure;
the a and b subunits.
proteins function as: (8)
- ENZYMES, selectively accelerating chemical reactions, such as digestive enzymes on hydrolyzing bonds inn food molecules
- STORAGE OF AMINO ACIDS, such as the ovalbumin, protein of egg white serve as storage of amino acid for the developing embryo.
- COORDINATOR OF AN ORGANISM’S ACTIVITIES such as insulin regulating blood sugar concentration.
- motor proteins for MOVEMENT such as actin and myosin for the contraction of muscles.
- PROTECTION AGAINST DISEASE such as antibodies inactivating bacteria and viruses.
- TRANSPORT OF SUBSTANCES, such as hemoglobin transporting oxygen.
- RESPONSE OF CELL TO A CHEMICAL STIMULI
- SUPPORT such as collagen and elastin providing a fibrous framework in connective tissues
are the one class of biomolecules that does not include true polymers, and they are generally not big enough to be considered as macromolecules
Lipids
Lipid’s hydrophobic behavior is based on their molecular structure and the three types of lipids are
fats, phospholipids and steroids.
Fats are constructed from two kinds of smaller molecules: (2)
glycerol and fatty acids
These are formed if there are no double bonds between carbon atoms composing a chain, then as many hydrogen atoms as possible are bonded to the carbon skeleton. They lack double bonds, and their flexibility allows the fat molecules to pack together tightly.
Saturated fatty acid
It has one or more double bonds , with one fewer hydrogen atom on each double-bonded carbon. Its double bonds are ___which has kinks to prevent the molecules from packing together closely enough to solidify at room temperature.
unsaturated fatty acid;
cis
When phospholipids are added to water, they self-assemble into double-layered structures called “______”, shielding their hydrophobic portions from water.
bilayers
The _________ are on the outside of the bilayer in contact with the aqueous solutions inside
and outside of the cell. The ________ point toward the interior of the bilayer, away from the water.
hydrophilic heads; hydrophobic tails
These are lipids characterized by a carbon skeleton consisting of four fused rings.
steroids
__________, a steroid, is a crucial molecule in animals since it is a component of animal cell membranes and is also the precursor from which other steroids are synthesized, such as the sex hormones
cholesterol
the most common monosaccharide, is of central importance in the chemistry of life.
glucose (c6h12o6)
Disaccharides are double sugars, consisting of two monosaccharides joined by a _________.
glycosidic covalent linkage or bond
surrounds the cytoplasm within cells, which in eukaryotes is filled with membrane-bound organelles.
Cell Membrane/Plasma Membrane
who made the model of the cell membrane,
trilamellar membrane structure in the electron microscope
J.D. Robertson
Trilamellar Membrane Structure in the Electron Microscope:
electron-dense layer: _________
electron-transparent layer:_____
electron-dense layer: proteins bound to phospholipids
electron-transparent layer:
fatty acid layer
membrane fluidity depends on ____, fatty acid ____ and ____:
- Temperature
- fatty acid saturation and cholesterol
higher temperature leads to ______fluidity
increased
more _____ fatty acids leads to more fluidity
unsaturated