module 1: what is life Flashcards
where do cells come from
pre existing cells
what does the structure of a cell or protein mean
the structure determines the function
can cells communicate with each other
yes they can
are virus alive
no
why are viruses not alive
because they are no comprised of cells, they cannot extract energy, cannot replicate
what are the 2 theory’s of the forces of life
1) life formed spontaneously
2) extra terrestrial life
what is a proto-cell
a lipid based semipermeable structure that allows some things in and some things out
- happens when lipids are put into water due to its hydroscopy properties
what are the 4 biomacromolecules
-proteins
-lipids
-carbohydrates
-nucleic acids
what are lipids comprised of
C, H and O
do lipids contains lots of oxygen
no, this means they are insoluble in water
why are lipids insoluable in water
because they are comprised of long hydrocarbon chains (non polar)
can lipids store energy
yes they can
what is a lipid made up from (structure)
phosphate head- which is hydrophilic water loving
fatty acid tail- hydrophobic (water hating)
what is a condensation reaction
building up a molecule, water is released
what is a hydrolysis reaction
breaking down of a molecule, water is needed
what are the 2 types of fatty acids
1) unsaturated
2) saturated
what is a saturated fatty acid
a fatty acid that only contains carbon carbon single bonds. this increases dispersion forces and allows these fatty acids to be solid at room temp
- more energy is required to break these bonds
what is an unsaturated fatty acid
a fatty acid that contains one carbon carbon double bond, these molecules are typically liquids at room temp because they contain a kink in the chain that decreased dispersion forces, thus less energy is needed to break the bonds
what are the 3 elements that a carbohydrate is made up of
C, H, O
what are carbohydrates used for
-source of energy
- structure (cellulose in plants)
what is the formular of a carbohydrate
(CH2)n
what is a monosaccharide
a single sugar molecule
what is a disaccharide
2 sugar molecules joined together
where is the hydroxyl group located on an alpha sugar
down the bottom
where is the hydroxyl group located on a beta sugar
up the top
what is a glycosidic link
the bond that joins 2 sugars together
-this bond is a —O— bond
- this process is known as condensation
what happens when glucose and glucose is bonded together
results in maltose (alpha 1-4)
what happens when galactose is bonded to glucose
results in lactose (beta 1-4)
what happens when glucose is bonded to fructose
results in sucrose (alpha 1-4)
what is cellulose
a long chain molecule that has little branching which creates a really strong cell wall
- a molecule in the cell wall of plants
is starch
- a molecule that used to store energy in plants
is starch branched
yes it is branched but only to a small degree
where does the branching occur in starch
at C1 and C6
what is glycogen
a molecule that stores energy in humans
is glycogen branched
yes
what are the bases in DNA
A, T, C and G
what are the bases in RNA
A, U, C and G
what are the pyrimidines
C, U, T
- only contain one hexagon
what is a purine
A and G
- contain 2 hexagons joined together
what direction does DNA run in
runs in a 5’ to 3’ direction
what bond joins 2 nucleotides together
a weak hydrogen bond
what is a monomer of a protein
amino acid
what does an animo acid consist of
- central carbon, hydrogen, R group, a carbonyl group and an amine group
what are some of the functions of proteins
- enzymes
- defense
- storage
- transport
- structure
what is a peptide bond
a bond that joins 2 amino acids together
-CONH
what is the n terminus
the end where the amine group is
what is the c terminus
the end where the carbonyl group is
what enzyme joins 2 amino acids together
peptidyl transferase
what is the primary structure of a protein
the sequence of amino acids
what is the secondary structure of a protein
the coiling and folding of the protein chain resulting in alpha helices and beta pleated sheets
what is the tertiary structure of a proteins
the 3D nature of a protein which is determined by the bonding and interrogations of the R group
what is the quartnary structure of a protein
where there are 2 or more polypeptides joined together
what bonds can be found in the tertiary structure
-hydrogen bonds
- ionic bonds
- hydrophillic bonds
-hydrophobic bonds
-van der waal interactions
- disulphide bridges
what bonds can be found in the tertiary structure
-hydrogen bonds
- ionic bonds
- hydrophillic bonds
-hydrophobic bonds
-van der waal interactions
- disulphide bridges
what is the smallest unit of life
cells
what are 2 types of prokaryotic cells
- bacteria
- archaea
what are prokaryotic cells comprised of
- circular DNA
- ribosomes
- generally smaller
what do prokaryotic cells lack
- no membrane bound organelles
- no nucleus
why are cyanbacteria important
becuase they were responsible for the oxygenation of the earth and were the first species to undergo photosynthesis
what is binary fission
the way of reproduction for prokaryotic cells
what are the steps of binary fission
- circular DNA is attached to the plasma membrane at a specific point
- DNA is replicated
- the new DNA is attached to a different point at the plasma membrane and the membrane will grow inwards
- this creates a new cell via cytokinesis
what qualifies a eukaryotic cells
- nucleus
- membrane bound organelles
- generally much larger
what surrounds the nucleus
the nuclear envelope
what is the purpose of the pores in the nucleus
- to allow genetic infomation out of the cell
- for example pre mRNA
what are chromosomes
a molecule that contains the genetic information of a cell
what are chromosomes made up of
made up of chromatin
what happens at the mitocondria
production of ATP
how many organelles does the mitochondria have
2
how occurs at the chloroplasts
photosynthesis
how many organelles does a chloroplast have
2
how many organelles does a chloroplast have
2
what is the origin of the mitochondria
- arose from purple bacteria
- formed a relationship with an aerobic bacteria
what is the evidence for endosymbiosis
- organelles are morphological similar
- they are double membrane bound
- they contain their own ribosomes
what is the endoplasmic reticulm made up of
cristernae
explain the SA:V of the ER
has a high SA:V ratio due to the folding
what are the two types of ER
- smooth ER
-rough ER
what occurs at the ER
site of synthesis of proteins, glycoproteins, carbohydrates and lipids.
what does the smooth ER synthesise
the smooth ER secretes carbohydrates and lipids
what is the function of the golgi body
responsible for the collection and packaging of molecules
what are lysosomes
they break down material ingested by endocytosis or recycle old organelles
what is it called when a lysosomes recycles an old organelle
autophagy
what do vacuoles do
preform a wide range of functions like storage of nutrients and maintain the cell structure
what are mircobodies
an organelles that contains enzymes to catalyse the breakdown of hydrogen peroxide (h2o2)
what are the 2 types of microbodies
-peroxisomes
and
-glyoxysomes
what do peroxisomes break down
amino acids
what do glyoxysomes break down
fatty acids
what occurs in the cytosol
a bunch of biochemical reactions
what is the role for the plasma membrane
to prevent the flow of lipids in and out of the cell due ti the hydrophobic middle region and protect the cells interior
is the plasma membrane a liquid
YES IT IS MOVING ALL THE TIME
does simple diffusion require energy
no
what is simple diffusion
the diffusion of a substrance from an area of high concentration to an area of low concentration
- along the concentration gradient
what is osmosis
the diffusion of water from an area of high solute concentration to an area of low solute concentration
what is a hypotonic solution
when the concentration of solution is lower than the concentration of the cell and thus water comes into the cell
what is a hypertonic solution
whe the concentration of solution is higher then the concentration of the cells and this water moves out of the cell and into the solution
what is an isotonic solution
both concentrations are the same and thus there is a net zero movement
what is faciliated diffusion
the use of transport proteins to move larger molecules into and out of the cell down the concentration gradient
what must happen for cell division to be success
the genetic material must be replicated accurately and distributed into the 2 daughter cells
what are the steps cell division in eukaryotic cells
interphase and mitosis
what are the 3 stages of interphase in order
1) G1
2) S
3) G2
what happens in G1
- organelles are made
- synthesis of proteins and enzymes
- growth
what happens at the s phase
- growth
- metabolic activity
- DNA replication
what happens in the G2 phase
-preparation for cell division
- growth
-metabolic activity
what stage does DNA replication take place
the s phase
what are the stages of DNA replication
- DNA helicase unwinds the DNA by disrupting the hydrogen bonds between the nitrogenous bases
- DNA polymease goes along the leading strand and creates a complimentary leading strand
what are the stages of mitosis in order
-prophase
-metaphase
-anaphase
-telephase
what happens in prophase
- chromosomes condense
- spindle fibres begin to form
what happens in metaphase
- nuclear membrane break apart
-spindle fibres attach to the chromosomes
-chromosomes line up to the equator of the cell
what happens in anaphase
-spindle fibres shorten (pulling the chromosome to one end of the cell
- centromere divides
- the production of 2 chromatids
what happens in telophase
- the nuclear membrane forms around each set of chromosomes
what
where are the checkpoints during cell division
-G1
-G2
- metaphase
what is the checkpoint at G1
cyclin CDKs prevent the progression of the cell cycle is ssDNA is found. this process activates the production of and ATR protein which halts the S phase
