AP Biology Final Review From Bart's Study Guide

Why is DNA replication said to be "semiconservative?

" Only some so the characteristics of the parent DNA are passed down the generations.

What are the end products of glycolysis?

2 ATP, 2 pyruvate, 2 NADH

What is the difference between the 5' and vs. 3' end of a polynucleotide strand?

5' has a phosphate on its top and 3' has a hydroxyl group on top

How does the percentage of each nucleotide type in a cell compare to each other?

A and T will equal and C will equal G Ex: (15% A + 15% T) and ( 35% C + 35%G) = 100%

What makes a substance hydrophobic?

A substance is hydrophobic when it is not polar like water which makes it repel water's polarity.

What are the base-pairing rules in DNA?

A with T: Purine Adenine always pairs with Pyrimidine Thymine C with G: the pyrimidine cytosine always pairs with the purine guanine

How does ATP generally energizes a cellular process?

ATP breaks off its last Phosphate, releasing free energy to the environment, powering many cellular processes

What does phosphorylation do to a molecule, both structurally and in terms of its energy content?

Adds a phosphate group to the molecule, raising the energy level

How is the synthesis of polysaccharides, lipids and proteins similar?

All are a result of monomers being connected through hydrolysis

Crossing over usually contributes to genetic variation by exchanging chromosomal segments between what?

An exchange of chromosomal segments between the chromatids in meiosis.

What are antigens?

Antigens are substances specifically bound by antibodies. They are substances that stimulate production of or are recognized by antibodies.

What happens if a human cell is placed in pure water?

As cells have particles inside of them, water will diffuse in and cause the cells to burst

How does the increasing complexity of living things relate to the second law of thermodynamics?

As organisms grow, entropy increases

What are the characteristics of the viral lytic and lysogenic cycles?

Attachment: attach to the cell mainly bacterial cell. Penetration: only nucleic acid is injected into the cell through the hole caused by the tail fibers and enzymes Synthesis: replication of viral nucleic acid and protein and envelope Assembly: spike proteins insert into the cell membrane, the capsid forms around the nucleic acid to form the mature virion. Release: usually by lysis through the membrane.

What did Avery and his colleagues show to be the transforming agent?

Avery and his co-workers found that the transformation of the bacteria was due to DNA. Previously, scientists thought that traits like this were carried by proteins, and that DNA was too simple to be the stuff of genes.

What would be the consequences of changing one amino acid in a protein?

Because the structure changes, the function could change

What is the ultimate source of carbon that is found in organic molecules?

Carbon Dioxide from atmosphere

Which property of the carbon atom gives it compatibility with a greater number of different elements than any other type of atom?

Carbon has four valence electrons which allows it to construct complex structures.

Which four elements make up approximately 96% of living matter?

Carbon, Hydrogen, Nitrogen, Oxygen (Phosphorus, Sulfur)

Why do receptor proteins in a membrane only recognize a specific chemical signal?

Cells have protein called receptors that bind to signaling molecules and initiate a physiological response. Membrane receptors interact with both extracellular signals and molecules within the cell, they permit signaling molecules to affect cell function without actually entering the cell.

How are the activities of mitochondria and chloroplasts similar and different?

Chloroplasts: create sugars that store energy, uses CO2 and releases O2 and H2O Mitochondria: uses sugars to produce energy, uses O2 and H20 to produce ATP and CO2

What factors can affect the activity of enzymes?

Concentration of enzymes, concentration of substrate, pH, temperature

What is the primary function of the light reactions in photosynthesis?

Convert light energy to make ATP and NADPH for the Calvin Cycle

Which enzyme catalyzes the elongation of a DNA strand in the 5' to 3' direction?

DNA Polymerase

What is the term used for a change in a protein's three-dimensional shape or conformation?

Denaturation

Why does a new DNA strand elongate m only in the 5' to 3' direction during DNA replication?

Each consecutive base is added to the open phosphate on top of the previous. Only the 5' end has a phosphate group. 3' has a hydroxyl group on its end.

Why is an ectotherm more likely to survive an extended period of food deprivation than the endotherm?

Ectotherms do not use energy to maintain body temperature, resulting in lower use of energy per unit of weight of organism than endotherms

How do enzymes affect chemical reactions?

Enzymes speed up the rate of chemical reactions by lowering the activation energy

What cell parts differ between a prokaryotic vs. a eukaryotic cell?

Eukaryotic: membrane bound organelles, nucleus Prokaryotic: flagella, free-floating DNA

What are the differences between a cancer and normal cell?

Evading growth suppressors—Normal cells are controlled by growth (tumor) suppressors. ... Cancer cells ignore these cells and invade nearby tissues. Benign (non-cancerous) tumors have a fibrous capsule.

What are the functions & products of the citric acid cycle?

Functions: produces NADH and FADH2 for the electron transport chain Products: 6 NADH +, H+ molecules, 2 FADH2 molecules, 4 CO2, and 2 ATP molecules.

What would be the ultimate result if the thylakoid membrane was "leaky"?

H+ would escape, and ATP production would discontinue

What is the difference in the way B cells and cytotoxic T cells respond to invaders?

Helper T cells are activated by interacting with antigen-presenting cells such as macrophages. They do not directly kill infected cells, as cytotoxic T cells do. Instead they help activate cytotoxic T cells and macrophages to attack infected cells, or they stimulate B cells to secrete antibodies.

In what situations will helper T cell be activated?

Helper T cells will be activated when it interacts with an antigen-presenting cell.

How did the Hershey and Chase experiment work?

Hershey and Chase concluded that DNA, not protein, was the genetic material. They determined that a protective protein coat was formed around the bacteriophage.

Why can humans digest starch but not cellulose?

Humans have enzymes that can hydrolyze the alpha glycosidic linkages of starch but not the beta glycosidic linkages of cellulose

What kind of chemical bond are found between paired bases of the DNA double helix?

Hydrogen bonds occur between the two strands and involve a base from one strand with a base from the second in complementary pairing.

Why does ice float in liquid water?

Ice is 9% less dense than water. Floats due to a crystal lattice structure that forms when frozen. Hydrogen bonds adjust to hold negatively charged oxygen ions apart.

What happens if mammalian cells receive a go-ahead signal at the G1 checkpoint?

If the mammalian cells receive a go ahead signal at the G1 (interphase) checkpoint, it then moves ahead to S phase and G2 phase and completes the cycle (either mitosis or meiosis).

What do cohesion, surface tension and adhesion have in common with reference to water?

It gives water special properties that allow it to have a high temperature absorption and allows it to be a universal solvent.

Energy released by the electron transport chain is used to pump H+ ions into which location?

Mitochondrial Intermembrane Space (area between the inner and outer membrane of the mitochondria)

What is active transport?

Movement of particles across the cellular membrane using energy to move the particles to a higher concentration using pumps and channels.

What is diffusion?

Movement of particles from a high concentration to lower concentration to reach equilibrium

What is endocytosis?

Movement of particles too large to pass through the pumps or channels

In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP+ Pi to ATP?

Movement of protons during ATP synthase (down electrochemical gradient)

What happens to depolarize the axon after an action potential?

Na pumps turn on to start pumping Sodium to remove the action potential and reset the axon to the inactive state.

What happens when the sodium gates open along an axon?

Na will flow into the axon

Neurotransmitters are released from presynaptic axon terminals into the synaptic cleft by which mechanism?

Nerve impulse release

The element nitrogen is present in what types of organic molecules?

Nucleic acids and proteins

What was Meselson and Stahl's experiment and what did its results look like?

Out of eighth resulting strands only two had the "heavy" strands of the parent DNA. This shows that none of the daughter DNA had both of the parent strands

What is the physiological action of each of these hormones: oxytocin, thyroxine, insulin, ACTH?

Oxytocin- contraction of the uterus (womb) during childbirth and lactations, it causes contractions. Thyroxine- is the main hormone secreted into the bloodstream by the thyroid gland. It plays an important role in regulating metabolic rate and body temperature. Insulin- helps to regulate blood glucose levels by signalling the pancreas to produce more when blood glucose levels are high. ACTH- is secreted from the anterior pituitary in response to corticotropin-releasing hormone from the hypothalamus, The function of ACTH is to regulate levels of the steroid hormone cortisol, which released from the adrenal gland.

What is the relationship between photosynthesis and cellular respiration?

Photosynthesis makes the glucose that is used in cellular respiration to make ATP. The glucose is then turned back into carbon dioxide, which is used in photosynthesis. While water is broken down to form oxygen during photosynthesis, in cellular respiration oxygen is combined with hydrogen to form water.

How are plant and animal cell structures similar and different?

Plant Cells: cell wall, chloroplasts, vacuoles Animal Cells: no cell wall, pinocytotic vesicles (the ones on the membrane going out)

Large numbers of ribosomes are present in cells that specialize in producing what type of molecules?

Proteins (protein synthesis)

What are the proteins that show fluctuations in concentration during the cell cycle and regulate its progression?

Proteins that show fluctuations in concentration during the cell cycle and regulate its progression are cyclins.

What are the structural differences between DNA and RNA?

RNA has a ribose sugar and DNA has a Deoxyribose sugar

What is feedback inhibition?

Reaction to end product that turns off the reaction producing the product

What is probably the most common route for membrane flow in the endomembrane system?

Rough ER → vesicles → Golgi Apparatus → plasma membrane

Which structure is the site of the synthesis of proteins that may be exported from the cell?

Rough Endoplasmic Reticulum

What is the difference between a saturated vs. unsaturated fatty acid?

Saturated fatty acids don't have any double bonds and are solid at room temperature; unsaturated fatty acids have at least one double bond and are liquid at room temperature.

What are the chromosomal differences between human male and female somatic cells and gametes?

Somatic cells are every cells in the body beside gametes. They are diploid and replicate through mitosis and used to repair damage tissue and grow. Gametes are sex cells, so the egg and sperm. They are haploid meaning they contain only half the number of chromosomes.

What are the three stages of cell signaling?

Stage one: Reception= a cell detects a signaling molecule from the outside of the cell. Stage two: Transduction = when the signaling molecule binds the receptor it changes the receptor protein in some way Stage three: Response = the signal triggers a specific cellular response.

What is the structure and function of antibodies?

Structure: each antibody consists of four polypeptides- two heavy chains and two light chains joined to form a "Y" shape. Function: Identify and neutralize foreign objects like bacteria and viruses

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

The DNA ligase combines the shorter fragments of DNA that make up the 5'-3' strand. This creates a continuous strand out of all the fragments.

Which cell type interacts with both the humoral (antibody-producing) and cell-mediated immune pathways?

The cell that interacts with both the humoral (antibody producing) and cell-mediated immune pathways is lymphocytes. The humoral response is mediated by B lymphocytes, which release antibodies specific to the infectious agent. The cell-mediated response involves the binding of cytotoxic T lymphocytes to foreign or infected cells, followed by the lysis of these

How does the hypothalamus control the anterior pituitary?

The hypothalamus communicates with the anterior pituitary through chemicals that are produced by the hypothalamus and delivered to the anterior pituitary through blood vessels in the infundibulum (brain stem). These chemicals release and inhibit hormones which are produced by specialized neurons of the hypothalamus, called neurosecretory cells. The hormones are released into a capillary network (primary plexus) and transported through veins (hypophyseal portal veins) to a second capillary network (secondary plexus) that supplies the anterior pituitary.

What is the primary function of the Calvin cycle?

The primary function of the calvin cycle is to change carbon dioxide into usable energy known as glucose. (the calvin cycle is the second stage of photosynthesis)

What happens during positive feedback?

The response to positive feedback is to continue the reaction and produce more of the hormone/product

What is the result of meiosis?

The result of meiosis is 4 haploid daughter cells with chromosomal combinations different from those originally present in the parent.

Why do the 20 different amino acids found in polypeptides exhibit different chemical and physical properties?

The side chains (R groups) change the properties

What does the sodium- potassium pump of neurons do?

The sodium-potassium pump uses energy to actively transport Sodium ions out of the cell and potassium ions into the cell across the membrane building up a chemical and electrical gradient for each. Ion channels can convert the chemical potential energy to electrical potential energy because of selective permeability. These gradients can also be used to drive other transport processes. In nerve cells the pump is used to generate gradients of both sodium and potassium ions. These gradients are used to propagate electrical signals that travel along nerves.

What does it mean that the strands that make up DNA are antiparallel?

The strands that make up DNA are antiparallel because they run in opposite directions of each other.

During signal transduction, the phosphorylation of proteins does what to those proteins?

They either stimulate or inhibit proteins

How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle?

They have the same number of chromosomes, resulting in the same amount of DNA/genetic material I gotchu

Why are phosphorylation cascades involving a series of protein kinases useful for cellular signal transduction?

This amplifies the signal allowing it to spread faster

How does the amount of DNA vary throughout the different stages of the cell cycle?

Throughout the stages of the cell cycle, the amount of DNA changes. During the G1 phase, each chromosome contains one molecule of DNA. But when the reproductive process begins, the cell will need two sets of DNA: one for itself and one for the offspring cell. During the S phase, the cell replicates its genetic material so that each chromosome will contain two molecules of DNA. During the G2 phase, the cell duplicates its organelles so that one set will be available for the offspring cell. Finally, the cell splits into two separate daughter cells.

Why do most molecular biologists think that viruses originated from fragments of cellular nucleic acids?

Viral genomes are usually more similar to the genome of the host cell than to the genomes of viruses that infect other cell types

What is the consequence of the lack of proofreading during the replication of the RNA virus' genome?

Viruses mutate their genome frequently

What is the explanation for why certain cells only respond to certain hormones?

While all cells are exposed to hormones circulating in the bloodstream, not all cells react. Only a hormone's "target" cells, which have receptors for that hormone, will respond to its signal. When the hormone binds to its receptor, it causes a biological response within the cell.

Grana, Thylakoids , and stroma are all components found in what organelle?

chloroplast

What are polysaccharides made of?

monosaccharides

What kinds of molecules pass through a cell membrane most easily?

nonpolar molecules + small polar molecules

Why do unsaturated fatty acids help keep membranes more fluid at lower temperatures?

permits movement of particles from higher to lower concentration

What are the components of innate immunity in humans?

physical barriers, leukocytes, dendritic cells, cocaine, natural killer cells, plasma proteins

What is the resting potential of a neuron?

slightly negative inside (-70mV)

What type of signal molecule can bind to an intracellular receptor and thereby cause a gene to be turned on or off?

steroid

What are the components of a nucleotide?

sugar, phosphate group, nitrogenous base

How do the two members of a pair of homologous chromosomes differ from each other?

the genome is composed of one set of each homologous chromosome pair, as compared to tetraploid organisms which may have two sets of each homologous chromosome pair. The alleles on the homologous chromosomes may be different, resulting in different phenotypes of the same genes.

What are membrane receptors that attach phosphates to specific amino acids in proteins called?

tyrosine kinases

What would happen if someone were transfused with the wrong blood cell type?

your immune system attacks the transfused red blood cells.