Bio AP Flashcards ദ്ദി૮ • ﻌ - ა✧

Biology AP flashcards for remembering all my weakspots

What is the structure of a water molecule?

1 oxygen atom covalently bonded to 2 hydrogen atoms

Describe water’s cohesive properties in molecular detail

Cohesion refers to molecules of the same type forming hydrogen bonds, this allows for the development of surface tension.

Describe water’s adhesive properties in molecular detail

Adhesion refers to molecules of different types forming hydrogen bonds, this allows for the development of capillary action in the correct conditions.

Describe why water is polar

The oxygen molecule has a higher electronegativity than compared to hydrogen. This results in water’s polarity

Can polar molecules form hydrogen bonds?

Yes, hydrogen bonds of polar molecules occur when oppositely charged regions of a molecule react

What bonds connect monomers?

Covalent bonds

Covenlently bonded monomers are used to build…

macro-molecules

Do all monomers contain carbon?

Yes

Dehydration synthesis makes or breaks macro-molecules?

Dehydration synthesis is used to create macro-molecules with water an additional product

Hydrolysis makes or breaks macro-molecules?

Hydrolysis uses water to cleave bonds and break up macro-molecules

What are the monomers of Nucleic Acids called?

nucleotides

What is the makeup of a nucleotide?

Nucleotides consist of a nitrogenous base, pentose sugar and a phosphate group

The difference between RNA and DNA?

DNA:

• Double-helixical structure

• Deoxiribonucleic sugar

• Adenine-Thymine, Cytocine-Guanine

RNA:

• Single stranded (typically)

• Ribonucleic sugar

• Adenine-Uracil, Cytocine-Guanine

Do variations in the sugar and base components of a nucleotide make a difference to function and structure?

Yeah

What gives amino acids directionality?

The amino terminus and carboxyl terminus (they also determine how amino acids assemble into protein polymers)

What is an R group?

In biology, the R group, also known as a side chain or alkyl chain, is a type of functional group. It is a chain of atoms, typically carbon atoms, attached to a carbon of an Rf atom ( or central atom) in an organic compound.

What is the function of an R group?

• Protein structure and function: R groups can affect the conformation and activity of enzymes, receptors, and other proteins.

• Metabolic pathways: R groups can influence the biochemical reactions and pathways involving enzymes, substrates, and cofactors.

How to R groups determine the function and structure of a protein?

By determining how aminos interact with the polypeptide

Are lipids polar or nonpolar?

Lipids are nonpolar macro-molecules

What is a key factor in determining the structure and function of lipids?

Saturation

Phospholipids contain polar regions, can these interact with other polar molecule and nonpolar regions?

Yes they hot-diggity-do

Is the hydroxyl group 5’ or 3’?

3’

Is the phosphate group 5’ or 3’?

5’

How many hydrogen bonds hold together the Adenine and Thymine base pairs?

2

A=T

How many hydrogen bonds hold together the Cytosine and Guanine base pairs?

3

C☰G

Which are base pairs are purines?

Adenine and Guanine

Which base pairs are pyrimidines?

Cytosine, Thymine and Uracil

How many hydrogen bonds hold together the Adenine and Uracil base pairs?

2

A=U

During RNA and DNA synthesis nucleotides can only be covalently added to which end of the growing nucleotide chain?

The 3’ hydroxyl group

What happens in Interphase?

the cell obtains nutrients and metabolizes them.

grows

replicates DNA

conducts other “normal” cell functions.

What happens in Prophase?

Chromosomes condense

Nucleolus membrane dissolves

What happens in Metaphase?

Chromosomes align along the metaphase plate

What happens in Anaphase?

Sister chromosomes are separated and pulled towards opposite ends of the cell by the spindles.

What happens in Telophase?

The spindle disappears and the nucleolus forms around the each set of daughter chromosomes, what follows is cytokinesis, where the cytoplasm is physically divided to form two daughter cells.

What is S phase?

Phase of interphase in which the cells DNA is replicated or synthesized.

What is G1 phase?

Part of interphase, in G1, the cell synthesizes mRNA and proteins in preparation for the next phases of the cell cycle.

What is G2 phase?

The period of rapid growth and protein synthesis that occurs before mitosis or meiosis.

What is the order of phases in interphase?

G1 (first growth), S (synthesis), and G2 (second growth)

What are feedback mechanisms?

Feedback mechanisms are processes that are used to maintain homeostasis by increasing or decreasing a cellular response to an event.

What is negative feedback?

Negative feedbacks maintain homeostasis by regulating physiological processes

What is positive feedback?

Positive feedback mechanisms amplify processes and responses and moves the system further away from homeostasis/equilibrium.

What are the key elements that make up proteins?

Carbon, Hydrogen, Nitrogen and Oxygen.

What are the four parts of a protein?

Proteins have 4 parts centered around a carbon: the amino group (-NH2), the carboxyl group (-COOH), a Hydrogen and an R group.

What differs between amino acids?

Amino acids differ only in the R-group, which is also called the side chain

and side chain polarity affects whether the amino acid is more hydrophobic or more hydrophilic.

The bond between to amino acids is called?

A peptide bond

Lipids are made of what elements?

Carbon, Oxygen and Hydrogen.

What is Glycolosis?

The splitting of glucose to form two pyruvate molecules.

How many ATP and NADH molecules are produced in glycolosis?

Net production:

• 2 ATPs

• 2 NADH

Where does glycolosis occur?

In the Cytoplasm

Where is pyruvic acid transported to and what does it go on to form?

Pyruvic acid is transported to the mitochondria and converted to acetyl-Co enzyme, while releasing C02

(this can enter many pathways but most commonly becomes a reactant in the citric acid or Kreb’s cycle)

Where is the electron transport chain located in a Eukaryotic cell?

The inner Mitochondrial membrane.

Where is the ETC located in prokaryotes?

The plasma membrane.

How is the ETC maintained?

the gradient is maintained as a result of the impermeability of the plasma membrane to charged ions and molecules.

What powers the production of ATP?

Protons moving through ATP synthase down the electrochemical gradient.

Factors that affect reaction rates?

Concentration of subtrate and/or enzyme, pH, temperature.

How is the energy in ATP released?

energy is released when the third phosphate is removed from the molecule forming ADP, a lone phosphate, and energy!

In other words, ATP is Hydrolyzed into ADP and an inorganic phosphate

When a leaf captures light energy, where does it go and what happens to it?

When a leaf captures sunlight, the energy is sent to P680, the reaction center for photosystem II.

The activated electron are then captured by the photosystem and passed down to carriers in the electron transport chain.

What is taxis (pronounced tax isss)?

Taxis is the movement of an organism in response to a stimulus, positive taxis being toward the stimulus and negative being away from the stimulus

Chemical taxis?

The Movement of an organism in response to chemicals

What is CAM photosynthesis?

CAM is a carbon fixation pathway evolved in arid plants that enables them to photosynthesize during the day, and exchange gasses during the night, ensuring minimal water loss.

Why does Cyclic Photophosphorylation occur?

Occurs because the Calvin cycle requires more ATP than NADPH, but the light reactions produce equal amounts of ATP and NADPH. So the plant compensates by going into cyclic phase to produce enough ATP to keep the light dependent reactions going. This process allows plants to generate additional ATP without producing more NADPH.

During which part of photosynthesis is Oxygen released and what molecule is it released from?

O2 is released during the light dependent reactions and from the photolysis of a water molecule

Where does CO2 enter the plant leaves?

CO2 enters the leaves through the stomata :)

what is G0 phase?

The state where cells have exited the cell cycle and remain inactive, cells in G0 are not preparing for division and this state can be temporary or permanent.

What is the null hypothesis?

the null hypothesis predicts no effect of the independent viable on the dependent variable and is accepted when the data shows no significant difference or pattern

Are sex cells haploid or diploid?

haploid

What are homologous chromosomes?

they are 2 copies but different versions of the same gene

What is the law of dominance?

One trait masks the effects of another trait.

what is the law of segregation?

each gamete only gets one of the copies of each gene.

Law of independent assortment?

Each pair of homologous chromosomes splits independently, so the alleles of different genes can mix and match during gamete formation.

What is a Barr body?

An inactivated condensed x chromosome, in every tissue in the adult female, one X chromosome remains condensed and inactive. However, this X chromosome is replicated and passed on to a daughter cell.

What is incomplete dominance?

Incomplete dominance is where traits blend e.g. a red flower and a white flower are crossed to produce a pink flower.

what is codominance?

the equal expression of both alleles e.g. AB type blood, where both the A and B alleles are expressed.

On pedigrees, traits that skip generations are usually…?

recessive.

Which Hardy-Weinberg equation is used to find allele frequencies?

p + q = 1

which Hardy-Weinberg equation id used to find genotype frequencies?

p² + 2pq + q² = 1

what is a plasmid?

small double-stranded, circular DNA molecules. The nucleotides can link up in a long chain to form a single strand of DNA that exist independently of chromosomal DNA in bacteria and can replicate independently.

what is the first step of DNA replication?

the first step is to unwind the double helix structure using the enzyme Helicase to break the hydrogen bonds between the complimentary nucleotide base pairs.

where does DNA replication begin?

it begins at specific sites called the origin.

which enzyme is used to stop the DNA strands from tangling up?

DNA topoisomerases prevent the tangling of the DNA strands by cutting and rejoining the helix. They help relieve the strain caused by unwinding during replication.

which enzyme adds nucleotides and where are they added?

DNA polymerase adds necleotides to the 3’ hydroxyl end of the growing DNA strand during replication.

what enzyme starts DNA replication

at the start of replication, an enzyme called RNA primase adds short strand of RNA nucleotides called a RNA primer.

After replication, the primer is degraded by enzymes and replaced with DNA so that the final strand contains only DNA.

what are Okazaki fragments?

small sections of DNA that are formed during discontinuous synthesis of the lagging strand during DNA replication.

which enzyme links the Okazaki fragments?

DNA ligase

what is transcription?

The process of making an RNA from DNA

what is translation?

the process of making a protein from an RNA

what are Exons

The regions of RNA that express the code

what are introns and what do they do?

The noncoding regions in the mRNA that allow for alternative splicing, which allows one gene to code for multiple transcripts and therefore serve multiple complex cellular functions

what is polycistronic transcript?

a process where prokaryotes will transcribe more than one mRNA from the same gene, so it can translated into multiple different proteins

what is monocistronic transcript and is this process found in prokaryotes or eukaryotes?

Eukaryotes tend to have one gene that gets transcribed to one mRNA and translated into one protein.

are the introns removed before or after the mRNA leaves the nucleus and what removes them from mRNA?

introns must be removed before the mRNA leaves the nucleus. This process, called splicing, is accomplished by an RNA-protein complex called a spliceosome.

what are the 3 binding sites of Ribosome? how is mRNA used in the Ribosome?

Ribosomes contain three binding sites: an A site, a P site, and an E site. The mRNA will shuffle through from A to P to E. As the mRNA codons are read, the polypeptide will be built.

what is the promoter gene?

The promoter gene is the region where the RNA polymerase binds to begin transcription.

what is the operator?

The operator is a region that controls whether transcription will occur; this is where the repressor binds.

what is the regulatory gene and what does it/its products do?

The regulatory gene codes for a specific regulatory protein called the repressor. The repressor is capable of attaching to the operator and blocking transcription.

what is morphogenesis?

when cell changes shape and organization many times by going through a succession of stages

what are Missense mutations?

Missense mutations cause the original codon to be altered and produce a different amino acid.

what are Nonsense mutations?

Nonsense mutations cause the original codon to become a stop codon, which results in early termination of protein synthesis.

what is synapsis and when does is occur in meiosis?

It occurs in prophase 1.

Synapsis involves two sets of chromosomes that come together to form a tetrad (a bivalent). A tetrad consists of four chromatids.

what is crossing over and when does it occur?

it occurs in meiosis 1 following synapsis, crossing-over, the exchange of genetic segments between homologous chromosomes, leading to increased genetic diversity.