Q4 Exam Flashcards
The 2 Types of Integral Proteins
Channel Proteins: Transports most of the ions and hydrophilic molecules through facilitated diffusion
Carrier Proteins / Protein Pumps: Transport molecules by active transport using ATP
Germ Cell Mutation VS Somatic Cell Mutation
Somatic occurs in body cells
Germ occurs in reproductive organs
Somatic is not passed onto offspring
Germ is passed onto offspring
Somatic can lead to health issues or diseases
Germ can directly affect offspring and all cells developed from the mutated zygote
Somatic is common
Germ is rare
Types of Base Substitution Mutations
Silent: Does not alter the amino acid sequence of the polypeptide, and occurs because of degenerate genetic code where multiple codons code for the same amino acid, which leads it to be unchanged
Missense: Causes the expression of a different amino acid
Nonsense: Adds a stop codon to the premature protein and stops protein synthesis
Sex-linked Dominant
Common in females
If a male shows a trait, then all his daughters and mother must
An unaffected mother can not have affected sons
Insulin and Function
Made of two polypeptide chains linked by disulfide bonds which is quaternary
Its shape allows it to bind to insulin receptors to regulate glucose uptake
Monozygotic and Dizygotic
Dizygotic (Fraternal): When two eggs are released during ovulation, they are both fertilized
Monozygotic (Identical): When one egg splits into two and both zygotes develop into separate individuals
Molecules that are Polar or Non-Polar
Glucose: Polar
Amino Acids: Depending on R group
Oxygen: Non-Polar
NaCl: Ionic
Fats: Non-Polar
Purpose of Control of Cell Division
Ensures that each daughter cell receives an exact copy of their parent’s DNA
Maintains proper cell numbers by preventing uncontrolled division
Allows for cell differentiation to create various cell types
Allows for organism growth, tissue repair, and wound healing
Hypotonic Effect in Plant Cell and Reason
Swells and becomes turgid as the plant cell has a strong cell wall which can build up turgor pressure
Difference with Cyclic and Non-Cyclic Photophosphorylation
Non-cyclic pathway of electrons
Cyclic pathway of electrons
PSI and PSII are used
Only PSI is used
Photolysis is required
Photolysis is not required
Source of electrons is water
Source of electrons is PSI
Products are ATP, NADPH, and Oxygen
Product is only ATP
Prophase Events
Chromatin condense into chromosomes by supercoiling and becoming visible
The nuclear membrane starts disappearing
Centrosomes move to opposite poles of the cell and the microtubules start to form
Kinetochores start to appear on centromeres
Glycolipid Protein Location and Function
Location: Phospholipids with carbohydrates attached, hydrophilic
Function: Cell recognition, identifies self and non-self cells, forms a layer with glycoprotein called glycocalyx which binds cells together and prevents the tissue from falling apart
Ratio of Unlinked Genes
Hetero with Hetero = 9:3:3:1
Hetero with Homo recessive = 1:1:1:1
Isotonic Effect in Animal Cell and Reason
No effect as water diffuses between outside and inside equally
Activation Energy
The minimum amount of energy required in order to start a reaction
The higher the activation energy, the slower the reaction
Enzymes reduce activation energy by distorting the shape of the substrate when it binds to the active site
Process of Crispr-Cas9 formation
Virus tries to invade bacteria
Bacteria fights back and grabs a fragment of virus DNA
The bacteria stores this snippet as a CRISPR sequence in its DNA
Over time, the bacteria collects many CRISPR sequences from different viruses forming a library
If the same virus attacks again, the bacteria recognizes it from its library and uses CRISPR sequence to guide Cas9 to virus’ DNA to cut the viral DNA
Gated Ion Channels
Three sodium ions bind on the sodium potassium pump in the intracellular space
ATP attaches to the protein and a phosphate group is transferred to the pump via hydrolysis
This causes a change in shape for the sodium pump, thus releasing the sodium ions into the exterior
Two potassium ions bind to different regions of the protein in the exterior surface which causes the release of the phosphate group
The loss of phosphate makes the pump revert back to its original shape and releases the potassium ions into the intracellular space
Interdependence of Light Dependent and Interdependent Reactions
Light independent reactions depend on dependent reaction for supply of ATP and NADPH. ATP and RedNADP are utilized in light independent reactions for the reduction of carbon dioxide into gluvose
Lack of light stops light dependent reactions and a lack of CO2 prevents PSII from functioning
Thermoregulation Mechanisms when Cold
Shivering: Muscles contract to generate heat
Vasoconstriction: Blood vessels in the skin constrict which reduces blood flow to minimize heat loss
Hairs Contract: Hairs stand, trapping a layer of insulating air next to the skin (Goosebumps)
Metabolic Rate Increases: Thyroid gland produces more thyroxin which increases body’s metabolic activity
Process of Ultrafiltration
Since the afferent arteriole is much larger than the efferent, it builds up hydrostatic pressure inside the capillaries, forcing fluids to pass from the blood through the fenestrated capillaries in the glomerulus into the Bowman’s Capsule
The liquid then drains through the Bowman’s Capsule to the Proximal Convoluted Tubule
Large molecules like blood cells and proteins can’t pass through the Bowman’s Capsule, therefore have to return to the blood through the efferent arteriole
The liquid that passes through the Bowman’s Capsule is called Glomerular Filtrate, and includes water, salts and amino acids
Mutations Classifications
Point Mutations: Base substitution
Frameshift Mutations: Insertion and Deletion
Post-transcriptional Modification
In eukaryotes, the mRNA has to undergo modification in order to become mature mRNA before it exits the nucleus
The non-coding introns are removed from the mRNA through RNA splicing, therefore having mature mRNA
mRNA gets addition of methyl group at the 5’ end called capping which provides protection against degradation by enzymes
mRNA gets addition of long chain of adenine bases at the 3’ end called polyadenylation which stabilizes RNA and facilitates its export outside the nucleus
Hypotonic Effect in General
Water moves by osmosis from lower solute concentration (outside) to higher solute concentration (inside), thus increasing the volume of the cell
Prophase I Events
Replicated chromosomes condense by supercoiling and becoming visible
Replicated homologous chromosomes pair up to form bivalent and undergo crossing over
Spindle fibers form and stretch out from each pole to the equator
The nuclear membrane starts to break down
Telophase Events
Microtubule spindle fibers disintegrate
The nuclear membrane reforms around the daughter chromosomes
Chromosomes uncondensed and coil back to become no longer visible
During the entire process of mitosis, the cell undergoes cytokinesis and ends in telophase
Starch Structure (Polysaccharides)
Consists of 2 types of molecules:
Amylose: Straight chain of alpha glucose units joined by 1-4 glycosidic bonds that coil up to form a helix which makes it more compact so resists digestion
Amylopectin: Branched chain of alpha glucose joined 1-4 with some 1-6 glycosidic bonds. Branches result in many free end glucose molecules that can be easily hydrolyzed
Type 1 VS Type 2 Diabetes
Insulin is not being produced
Pancreas doesn’t respond to insulin
Genetic and environmental factors
Age and diet and genetics
During childhood
During adulthood
No proven cure
Lifestyle modifications such as diet and exercise
Requires insulin injections to regulate blood sugar
Medication and managing lifestyle
Structure of the Cells of the Tubules Adapted for Reabsorption
Microvilli: Increase the surface area of the inner surface
Pumps: Actively transport glucose and amino acids against their concentration gradient
Mitochondria: Provides ATP needed for Selective Reabsorption
Linked Genes
Genes are found on the same chromosome pair
Chromosomes don’t assort independently and tend to be inherited together
Recombination only occurs if crossing over occurs
The closer two alleles are on a chromosome, the less likely crossing over will occur, vice versa
Have fewer recombinants than unlinked genes
Represented as AB//ab
Cellulose
Straight parallel chains of beta glucose joined by a condensation reaction with 1-4 glycosidic bonds
Each glucose molecule flips 180 degrees leading to glycosidic bonds alternating up and down
Hydrogen bonds form between parallel chains which cause the formation of microfibrils which are very strong
Microfibrils give cellulose fibres a very high tensile strength and allow a cell to withstand large pressures from osmosis
The function of cellulose is to provide strength for cell walls in plant cells
Cytokinesis in Animal Cell
A contractile protein ring forms around the equator of the cell and pulls the plasma membrane inwards. This inward pull is called the cleavage furrow, and when the cleavage furrow reaches the center of the cell it is pinched apart to form two daughter cells
Meiosis I VS Meiosis II
Synapsis and crossing over occurs in Prophase I
Synapsis and crossing over doesn’t occur in Prophase II
Homologous pairs of chromosomes line up in the equator
Sister chromatids line up in the equator
Homologous pairs of chromosomes separate and move to opposite poles of the cell
Sister chromatids separate and move to opposite poles of the cell
2 haploid cells are formed
4 haploid cells are formed
Conserved and Highly Conserved Sequences
Conserved: Identical or similar across a species or group of species
Highly Conserved: Identical or similar along long period of evolution
Functions of the Plasma Membrane
Structural (keeps cell contents together)
Serves as the boundary between the cytoplasm and the external environment
Maintains stability and fluidity of the cell
Provides cell-to-cell communication by different mechanisms
Controls what enters and exits the cell
What Separates Glomerulus and Lumen
Endothelium: 1 cell thick with more gaps than other capillaries
Basement Membrane: Made of network of collagen and glycoprotein
Podocytes: Cells that wrap around the capillaries of the glomerulus
Role of Enzymes in DNA Replication
Gyrase decreases helical strain just ahead of Helicase
Helicase unwinds the DNA double helix by breaking the hydrogen bonds between the bases, separating it into two strands
Primase is an RNA polymerase which adds RNA primer at the 3’ end of each template strand to act as the starting point of replication
DNA Polymerase III binds to the primer and moves in opposite direction (5’ to 3’) and adds free nucleotides to each strand using complementary base pairing
DNA Polymerase I removes the RNA primers and replaces them with DNA
Ligase seals up the Okazaki Fragments together after Primers are removed to form a continuous strand
Brain in Sleep, Vigorous Exercise, and Wakeful Rest
Sleep: High to support essential functions such as memory
Vigorous Exercise: High to meet the high metabolic demands and maintain cognitive function and coordination
Wakeful Rest: High to sustain cognitive function and consciousness while the body is awake and alert
Features of a Competitive Inhibitor
Has a similar structure to the normal substrate
Binds with the active site, and therefore competes with the substrate for the active site, thus reducing the number of enzyme-substrate complexes
Can be overcome with increasing substrate concentration
Rate will eventually reach maximum
Solubility of Carbohydrates, Fats and Proteins
Carbohydrates: Only sugars are soluble
Fats: Low solubility is soluble
Proteins: Some are soluble
Glucagon and Raising Blood Glucose
Alpha cells in the pancreas produce glucagon in response to low blood sugar to raise it
Glucagon prevents the conversion of glucose into fatty acids for storage, breaks down glycogen into glucose, and decreases respiration
Collecting Duct
After loop of Henle, the fluid moves to the collecting duct where the high solute concentration establishes an osmotic gradient. Water in the filtrate can passively diffuse out into the blood thus making the urine more concentrated
The water leaves through aquaporins which are controlled by ADH, which allows for the amount of water in urine to be controlled
Hemoglobin and Function
Transport protein
Made of 4 polypeptide chains and has 4 heme prosthetic groups
Each heme group binds to oxygen and transports it with the red blood cell
Conditions for Ultrafiltration
Hydrostatic Pressure due to the difference in diameter between afferent and efferent arteriole
Basement Membrane to restrict the passage of large molecules such as blood cells and proteins
Triglycerides Structure
Made of a glycerol backbone attached to 3 fatty acids in a condensation reaction and joined together by ester bonds
Blood Groups and Alleles
A - I^A
B - I^B
IA - I^AI^B
O - i
A and B code for enzymes that add specific sugars to a glycoprotein on the RBC
LDR VS LIR
LDR takes place only in presence of light
LIR takes place in presence and absence of light
LDR takes place in thylakoid mb
LIR takes place in stroma
LDR converts light energy into chemical energy
LIR use the chemical energy to fix CO2
LDR has photolysis occur in PSII
LIR has no photolysis
Gut in Sleep, Vigorous Exercise, and Wakeful Rest
Sleep: Low as body’s metabolic activity decreases
Vigorous Exercise: Low as blood is redirected to other vital organs involved in exercise
Wakeful Rest: Moderate to support ongoing digestive processes and nutrient absorption from food intake
Applications of Gene Editing
Correcting genetic diseases
Developing new therapies for cancer and other illnesses
Engineering crops with desirable traits like resistance to pests or diseases
Post-translational Modification
Polypeptides get modified to make them fully function. Examples of modification include
Removal of methionine from 5’ end
Changes to side chains of amino acids
Folding of polypeptide or combining two or more polypeptides
Mode of Transport for Molecules
Glucose: Dissolved in blood plasma
Amino Acids: Dissolved in blood plasma
Oxygen: Attaches to the hemoglobin of the RBC
NaCl: Ionizes into Na and Cl in plasma
Fats: Carried in blood plasma inside lipoprotein complexes with a single layer of phospholipids
Afferent and Efferent Arterioles
Blood arrives to the nephron in the afferent arterioles and delivers to network of capillaries called a glomerulus in a cup shaped structure called Bowman’s Capsule
Blood leaves the glomerulus in the efferent arteriole which is narrower than the afferent arteriole
Parental VS Recombinant Geno and Phenotypes
Phenotypes of offspring often resemble (at least 1) parents
Phenotypes of offspring differ from both parents
Genotype shows that traits are either dominant or recessive
Genotype shows that one trait is dominant and one recessive
Transcription VS Translation
DNA gets transcribed
RNA gets translated
Takes place in nucleus
Takes place in cytoplasm (ribosome)
mRNA is produced
Polypeptide is produced
Sickle Cell Anemia Altered RBC
DNA sense strand is GTG
DNA template strand is CAC
mRNA is GUG
Valine which is hydrophobic and makes hemoglobin less soluble
Sickle Shaped
Difference with Endothermic and Exothermic Reaction
Endothermic is Anabolic
Exothermic is Catabolic
Endothermic requires energy
Exothermic releases energy
Energy of products is more than energy of reactants in Endothermic
Energy of products is less than energy of reactants in Exothermic
Glycogen Structure (Polysaccharide)
A multi-branched polysaccharide that consists of many alpha glucose joined through a condensation reaction, linked by both 1-4 and 1-6 glycosidic bond
Highly branch which makes it compact and useful for energy storage
High amount of branches provides more free ends which allows glycogen to be broken down quickly for glucose in respiration
Solute Potentials
The concentration of solute particles
High solute concentration = Less potential energy
The higher the solute concentration, the lower the water potential, the more negative the value is
Water moves from high to low water potential
Difference with a Conjugated and Non-conjugated Protein
Conjugated: Combined an inorganic component called a prosthetic group
Non-conjugated: Made of polypeptide chain that is not associated with other chemical groups
Steroids Structure
4 linked carbon rings
3 cyclohexane rings and 1 cyclopentane ring
17 carbon atoms in total
Triglycerides Function
Energy Storage: Triglycerides are highly stable so energy is not lost over time, highly reduced so release twice as much energy, and insoluble in water so they remain localized
Thermal insulation: Triglycerides are poor thermal conductors therefore trap heat and maintain internal body temperature, with the thicker the layer of adipose tissue the increased retention of heat which helps mammals who live in cold environments such as Gavia Artica and Pusa Hispida
Differences between Carbohydrates and Lipids (Glycogen and Triglycerides)
Carbs are stored in the liver as glycogen
Lipids are stored in adipose tissue as fat
Carbs are short term energy storage
Lipids are long term energy storage
Carbs contain less energy per gram than lipids
Lipids contain more energy per gram than carbs
Carbs release energy fast and easily digested
Lipids release energy slow and less digested
Carbs needs less oxygen to release energy
Lipids needs more oxygen to release energy
Pressure Potentials
Pressure exerted by water in a system to stop the flow of water down its gradient
Positive Pressure: Pressure in system is greater than environment
Negative Pressure: Pressure in System is less than environment
The higher the pressure, the higher the water potential, the more positive the value is
Water moves from high to low pressure
Difference with Cis and Trans Isomers
Cis is healthy, natural, and found in nature
Trans is unhealthy, rare, and artificially made
The hydrogen atoms in Cis are on the same side of the double carbon bond
The hydrogen atoms in Trans are on opposite sides of the double carbon bond
In Cis, the double bond causes a kink in the fatty acid chain
In Trans, the double bond doesn’t cause a kink in the fatty acid chain
Cis has lower melting point
Trans has higher melting point`
Epigenetic Tags
Chemical modifications to the DNA and histones which regulate gene expression
These modifications change the phenotype without changing the genotype which affects how cells read the genes
Epigenesis is essential for normal development and is associated with aging and various diseases including cancer
Autosomal Dominant
Appears almost in both males and females equally
All affected individuals must have an affected parent
Trait doesn’t skip generation
Unaffected parents must produce unaffected offspring
Affected parents can have unaffected child
Differences with Simple and Facilitated Diffusion
Simple Diffusion moves directly through the phospholipid bilayer while facilitated diffusion doesn’t move directly through
Simple diffusion doesn’t involve a channel protein while facilitated diffusion uses channel proteins
Simple diffusion transports hydrophobic molecules while facilitated diffusion transports hydrophilic molecules
Simple diffusion is slower and facilitated diffusion is faster
Homologous Chromosomes
Pairs of non-identical chromosomes in a diploid cell that are inherited from parents. They have same length, gene sequence, centromere positions, and same gene locus. They only differ from each other by alleles
Metaphase Events
Nuclear membrane disappears completely
Microtubules grow and attach to centromere’s kinetochores, and move them to align both sister chromatids towards the equator of the cell
Each sister chromatid faces a pole, and the spindle fibers are fully developed
Rubisco and Function
Has a rounded shape that is tertiary, which provides three dimensional active site where a substrate can bind
The prosthetic group can be a metal ion
Translation
The synthesis of polypeptides with a specific amino acid sequence that is determined by their base sequence on the mRNA molecule
Occurs in cytoplasm and requires tRNA, mRNA and ribosomes