PWSH AP Bio Review

Flashcards based on lecture notes covering cell structure, function, cell signaling, and related concepts.

What is peptidoglycan?

A protein sugar cell wall found in Gram-positive bacteria.

What is cellulose made of?

Lots of glucose molecules.

What are ribosomes?

Organelles where the primary structure is made up of ribosomal RNA and proteins.

Do Prokaryotes have membrane-bound organelles?

No, prokaryotes only have things that are NOT membrane-bound.

What is the cell membrane made of?

Phospholipids and is fluid.

What comprises the lipid bilayer cell membrane?

ALL cells have a phospholipid bilayer (cell membrane).

What is the function of the smooth ER?

Detoxifies alcohols and drugs, phospholipid synthesis, and calcium storage.

What is a vesicle?

A membrane sac that can hold things.

What are chromosomes wrapped around?

Histone proteins.

What is the size of prokaryotic ribosomes?

70 S

What is the size of eukaryotic ribosomes?

80 S

Where do eukaryotic ribosomes sort and fold proteins?

ER, Golgi, and vesicles.

Where do prokaryotes synthesize ATP?

Cell membrane (some in cytoplasm).

What is the function of lysosomes?

Recycles anything that can be recycled into macromolecules.

Do animal cells have permanent vacuoles?

No, animal cells do not have permanent vacuoles.

What are the key differences between prokaryotes and eukaryotes?

Prokaryotes: single cell, no membrane organelles, single chromosomes, circular DNA, binary fission. Eukaryotes: single OR multicellular, have membrane-bound organelles, linear DNA, paired chromosomes, sexual and some asexual reproduction.

What is the invagination theory?

Scientists think that the 1st organelles were formed by accident, the origin of membrane-bound organelles.

What is the function of peroxisomes?

Break down fatty acids and produce H2O2.

What is the function of catalase?

Breaks down hydrogen peroxide since it very dangerous to cells.

What is the function of pseudopodia?

throw cytoplasm around to move

Why do eukaryotic cells compartmentalize?

Allows incompatible processes to occur and to "Divide and conquer".

What is the Endosymbiotic Theory?

Eukaryote consumes an aerobic bacteria that evolved into mitochondria

What do cells increase to increase SA:V ratio?

Unique shapes that increase the amount of membrane.

What bases do both prokaryotes and eukaryotes have?

The same 4 bases that translate into the same 20 amino acids.

Why do eukaryotic cells have to be big?

Because they have so many compartments.

What is the endomembrane system?

Includes the nuclear envelope, smooth and rough ER, Golgi, lysosomes, vesicles, vacuoles, and plasma membrane.

What happens to mRNA after it leaves the nucleus?

It is hoping to randomly collide into the ribosome, so that the small subunit will read mRNA and the large subunit will hold the mRNA

What happens to a protein in the cytoplasm?

A protein gets into a chaperonin protein when it finished as a protective environment and let the protein fold into its primary, secondary, tertiary and maybe quarternary structures inside chaperonin

What protects cells from the outside environment and plays a role in cell communication?

Cell membranes

Fluid Mosaic Model

Fluid, bc moves in space around the cell membrane, a million flips per second, even moving across lipid bilayer from each other and Mosaic, bc not just phospholipids in the membrane, there are also proteins, cholesterols, etc.

What helps spread the membrane out, facilitating better diffusion of O2 and CO2 when COLD; fill in gaps and whole proteins when it is HOT?

Cholesterol

What membrane proteins are important for cell signaling and enzymes?

Peripheral proteins

What type of transport needs ATP?

Active transport

What are desmosomes, plasmodesmata, gap junctions, and tight junctions?

Membrane junctions

What is osmosis?

Water moves down the concentration gradient

What molecules get through the phospholipid bilayer on its own?

Small, nonpolar, not charged

What transports water rapidly?

Aquaporin protein

What is phagocytosis?

Bringing something big in to eat, pinch off into vesicle and fuse with lysosome and break contents down into usable components

What is receptor-mediated endocytosis?

Looking for something very specific to bring into the cell, does that by using receptor protein to look for something very specific and brings that specific thing into the cell by invagination

What is Turgor pressure?

Stiffness caused by pressure.

What is a typical resting potential for neurons?

-70 MV

What do Schwann cells produce?

Myelin sheath and lipid cells

What is the function of Leak Channels?

Permits ions to flow down concentration gradients

What opens ligand-gated Na+ channels, allows Na+ to flow in, and the cell becomes less negative?

EPSP neurotransmitters

What are the three main stages of cellular signaling?

Receiving a message, signal transduction, and forming a response.

What is the function of ligands in cell signaling?

Signaling molecules that are going to hit a receptor and will not be consumed.

What are the most common receptor types?

Ligand-gated ion channels, G Protein-coupled receptors (GPCR), Tyrosine kinase receptor, and Nuclear (cytosolic) receptor

What are the cytoplasmic secondary messengers?

Amplify original signal and activate intracellular signaling pathways.

What is the function of Necrosis?

Cell is injured, loss of plasma membrane integrity, and leakage of cellular contents and is UNPLANNED.

What is the function of Apoptosis?

Cell shrink, plasma membrane blebbing and forming vesicles for WBC to eat (apoptotic bodies). It is PROGRAMMED, it is getting a signal to die.

What is substrate-level phosphorylation?

To take a phosphate from a high energy molecule and put it on a molecule with ADP to make ATP

Bacterial ETC:

pump proteins between cell membrane and cell wall (periplasm) (bc no mitochondria) they only have 2 proteins that pump H+ (dehydrogenase and reductase). Dehydrogenase takes both FAD and NAD as they do Krebs cycle.

Fermentation:

partially oxidizes glucose, produces 2 ATP, uses ONLY glycolysis, and is a last ditch way to regenerate NAD+. This is NOT a form of anaerobic respiration

If NADP+ is not available (wasn’t regenerated) then occurs

cyclic electron flow

How do CAM plants carry out carbon fixation and the Calvin Cycle?

CAM: at night open stomata let all co2 come in and at morning close stomata: separates initial carbon ifxation and calvin cycle

In DNA, where does the nitrogenous base hang off?

Carbon #1

Heterochromatin is when . Euchromatin is when ____.

DNA is wrapped too tightly around histones; histone proteins are tagged with an acetyl tag, which tells histone proteins to wrap loosely around dna

Which enzyme prevents supercoiling ahead of helicase?

Topoisomerase

Where does DNA duplication occur?

S(synthesis) phase

Centriole:

Structure found in pairs, made of triplets of microtubules

The G1 checkpoint:

Checks if cell GREWW, if cell made more phospholipids, if it gained growth factors, if DNA is damaged.

Why needs TRK receptors?

to ensure message is loud

Is G2 checkpoint is hard or soft checkpoint?

hard checkpoint

A centromere is ., Kinetochore is _.

a piece of DNA / a patch of protein

Oncogenes:

mutated overactive positive regulators

Proto-oncogenes:

normal, not yet mutated positive regulators, group of genes that cause normal cells to become cancerous when they are mutated

Negative regulators act as ___.

Tumor suppressor

The Chi-Square null hypothesis indicates that,

no substantial statistical di erence between observed and expected values [no change, basically everything is due to chance]

Sexual reproduction:

half chromosmes come from mom and half comes from dad

Dominant Gene:

Functional protein made and the product can be seen (brown eyes)

Non-Mendelian Genetics:

don’t follow the simple dominant and recessive inheritance pattern

Epistasis:

one gene can mask/modify another gene

Heterozygous phenotype same as that of homozygous dominant;

Complete Dominance (Mendelian)

One gene is able to affect multiple phenotypic characters;

Pleiotropy

Which is inherited only through the mom: mitochondrial dna or x-linked dna?

mitochondrial dna

If it’s recessive (autosomal recessive or x-linked recessive), then it will

skip a generation

The central dogma states:

take dna transcribed into mrna transcribed into a protein

UTRs:

untranslated regions, markers for ribosome (caps)

Prokaryotes and Eukaryotes:

Prokaryotes don’t have a nucleus, so they cannot splice out introns and pair their transcription and translation. Eukaryotes: our transcription + translation is separated by space (nucleus, cytoplasm)

Alternative splicing:

NOT splicing of introns, but there are alternative ways of splicing exons together. Came up with this through trial and error. Exons that are spliced will be recycled

polycistronic vs. monocistronic:

how many products get made from mrna

Retroviruses:

viruses don’t do transcription and translation, violate central dogma

Nonsense Mutation:

when one of amino acids is switched out from early stop codon

A group of rna virus that injects its rna in a host cell AND use enzymes to reverse transcribe their RNA into DNA

Retroviruses

Histone acetylation:

adds an acetly tag which opens chromatin and promotes transcription.

microRNAs:

will bind to the mRNA and if it is perfectly matching to the mRNA, it will break the mRNA up (like a ribozyme) and if it partially matches the mRNA, it will bind to the mRNA and ribosome will not be able to fit and translate the mRNA

Translation:

translational control- stop translation from occurring. Ribosomes made of rRNA and protein, if tag a ribosomal protein can change it. (eIF2 can be phosphorylated to block transcription (as the phosphorylation will pull the eIF2 away))

Prokaryotic Gene Expression:

only regulate gene expression at the transcription level (genes will be transcribed ONLY when needed, so if genes are not needed transcription is blocked)

For example, a lac operon is , meaning it can be turned on.

INDUCIBLE

The phylogenetic tree shows .

relationships, what do we have in common what do we not have in common: SHARED CHARACTERISTICS

A clade is:

a group of species that includes an ancestral species and all its descendants(ancestor + ALL descendents)

Evolution & Natural Selection:

We are most closely related to archaea than bacteria, even though archaea are ANCIENT (simply because we both have histones)

Important things to remember about phylogenetic trees is:

we don’t know the timeline, so we don’t know if A came before B and B came before D, IT’S A TREE, NOT A LADDER; as move to right, it does not mean it’s more advanced; where everything is does not matter (it can go A, B, C, & D OR B, C, D, & A)

Who has fewest evolutionary events occur?

Maximum parsimony:

An adaptation is .

an inherited characteristic of an organisms that enhances its survival and reproduction in an environment

The fish cannot evolve _.

into piranha

Heterozygous advantage:

Heterozygous advantage (like sickle cell) [bad allele is recessive but bc being Ss is better as can’t get malaria but no sickle cell, most ppl are Ss and if Ss and Ss get together, then deleterious allele (ss) made]

Morphological Species:

if you have one of these things then ur same species ; defines a species by body shape and structural features, it’s the oldest method, scientists use it to distinguish between species

Phylogenetic Species Concept:

smallest group of individuals that share a common ancestor and form one branch on tree of life

Biological Species Concept:

a group of populations whose members have potential to interbreeed in nature AND produce viable babies, who can make viable babies