AP Biology Study Guide Flashcards

AP Biology exam preparation flashcards focusing on Chemistry of Life, Cell Structure and Function, Cellular Energetics, Cell Communication and Cell Cycle, Heredity, Gene Expression and Regulation, Natural Selection, and Ecology.

What percentage of the AP Biology exam covers Chemistry of Life?

8–11%

What two molecules covalently bond to form water?

Two hydrogen molecules covalently bonded to an oxygen molecule.

What type of bond forms between a proton in one molecule and an electronegative atom of another molecule?

Hydrogen bonds

What property of water occurs when molecules of the same kind stick together?

Cohesion

What property of water is the tendency of dissimilar molecules to be attracted to each other?

Adhesion

What four elements comprise 99% of all living matter?

Carbon, Hydrogen, Nitrogen, and Oxygen

What unique chemical property does carbon have that makes it ideal to form the backbone of complicated biological molecules?

Being able to form four bonds with other elements.

What are the four major biological macromolecules?

Carbohydrates, Proteins, Lipids, and Nucleic Acids

What type of molecule is made of repeating smaller units called monomers?

Polymers

What process do macromolecules form through?

Dehydration synthesis of monomers

What is the reverse process of dehydration synthesis called?

Hydrolysis

What are proteins made of?

Strings of amino acids connected by covalent bonds

What is the basic structure of an amino acid?

A central carbon atom with an amino group (NH2) on one side, a carboxyl group (COOH) on the opposite side, a hydrogen atom, and an R group that determines the identity of the amino acid.

What are covalent bonds of amino acids called?

Peptide bonds

What gives rise to the secondary structure of proteins?

Interactions between elements in the amino acid backbone (not including R groups).

What do carbohydrates form that is an important structural element of organisms?

An immediate source of energy

What is the formula for carbohydrates?

(CH2O)n, where n refers to the number of times this structure repeats.

What is the covalent bond formed between a carbohydrate and another molecule called?

Glycosidic bond

What are lipids made of?

Nonpolar macromolecules made of hydrocarbon chains

What is a fat, or triglyceride, made of?

A glycerol backbone and three fatty acid chains.

What is the difference between saturated and unsaturated fats?

If all neighboring bonds in the hydrocarbon chain are single bonds, the fatty acid is called saturated. If there are double bonds in the chain, the fatty acid is called unsaturated.

What are the components of a nucleotide?

A sugar (deoxyribose), a phosphate group, and a nitrogenous base.

What are the four varieties of DNA nucleotides?

Adenine (A), Thymine (T), Guanine (G), or Cytosine (C).

What is used in RNA instead of thymine?

Uracil (U)

What are G and A molecules called?

Purines

What are C, T, and U called?

Pyrimidines

How do two strands of DNA connect together through complementary base pairing?

One strand will have a 3’-5’ directionality, and the second strand will be oriented in the 5’-3’ direction.

What is the key difference between RNA and DNA?

RNA is the sugar group and has uracil (U) instead of thymine.

What are the two categories of cells?

Prokaryotes and Eukaryotes

Do prokaryotes have cell walls or membrane-bound organelles?

No

What is the difference between animal and plant cells?

Animal cells have a thin plasma membrane, whereas plants have a cell wall in addition to the plasma membrane made of cellulose and lignin.

What is the function of the cell wall?

Giving strength, rigidity, and protection to plant cells. Helps the cell store water by regulating diffusion and providing the strength to allow high internal pressures without rupture.

What is a central vacuole?

A fluid filled membrane-bound structure that stores water and nutrients for the cell.

Where does RNA transcription occur?

Within the Nucleus

What organelle performs translation of RNA into protein?

Ribosomes

What make up the cytoskeleton?

Microtubules, intermediate filaments, and microfilaments

What is the function of vesicles?

Membrane sacs that transport molecules in a cell.

What does the fluid mosaic model describe?

The structure of cell membranes.

What is the main function of the cell membrane?

Creating selective permeability, meaning that only certain molecules can pass through the membrane.

What are the three forms of passive transport?

Simple diffusion, facilitated diffusion, and osmosis.

What is osmolarity?

The total concentration of solutes in a solution.

What is the process by which water moves across a semipermeable membrane from an area of low concentration of solutes to an area of high concentration of solutes, to equalize concentrations called?

Osmosis

What does tonicity refer to?

The ability of water to move across a membrane by osmosis

What are the three environments plant cells can be in?

Isotonic, hypertonic, hypotonic

What is one essential feature of cellular environments?

Compartmentalization of Processes

Membrane bound organelles evolved from prokaryotic cells through what process?

Endosymbiosis

What is a catalyst?

A substance that reduces activation energy and increases reaction rate without itself undergoing a chemical change

What is the substrate?

The molecule that the enzyme binds with to facilitate a change

What are the negative factors that can affect enzyme reaction rates?

Inhibitors

What is metabolism?

All energy transformations in living organisms, including processes like photosynthesis, mitochondrial respiration, and movement.

What is the process where molecules store energy in the form of chemical bonds called?

Anabolism

What is the process by which energy is released by breaking bonds called?

Catabolism

What is adenosine triphosphate (ATP)?

The primary source of energy that cells use to function.

What is NADPH?

An electron carrier used in biological reactions.

What is fixed carbon?

Organic carbon molecules, like sugars.

What are the names of electron carrier molecules?

NADH and FADH2

What is the final electron acceptor in oxidative phosphorylation?

An O2 molecule, which generates water.

What are the two main communication signals between cells?

Long Range and Short Range Signals

What is the name of a molecule released in extracellular space to be received by another cell?

A ligand

What are the four cell communication methods?

Paracrine, Autocrine, Endocrine, Cell-Cell Contact

What is negative feedback?

Mechanisms help to return a system to its set point after a disruption

What is positive feedback?

Response to a signal amplifies the response so that there is a quick change

What are the five stages of Mitosis in order?

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

What are the checkpoints within the cell cycle?

G1 checkpoint, G2 checkpoint, M checkpoint

What are positive regulators of the cell cycle?

Molecules called cyclins and cyclin dependent kinases (CDKs)

What are negative regulators of the cell cycle?

Tumor Suppressor Proteins

What process forms four daughter cells with half the amount of DNA as a normal cell?

Meiosis

What does homologous chromosomes mean?

Non-identical copies of each chromosome

What chromosomes do gametes (sperm and egg) have?

Haploid Chromosomes, meaning possessing only one copy each

What is Crossing Over?

During prophase 1, homologous pairs of chromosomes align and exchange DNA

What does Independent Assortment cause?

Diversity ensures only a haploid set of chromosomes is received from parents

What do alleles encode?

Alleles in classical genetics are considered dominant or recessive. A dominant allele masks the effects of a recessive allele.

What does the notation Punnett Square do?

Used to predict possible offspring of two parents

What is the term for multiple genes controlling inheritance?

Polygenic

What is Semiconservative Replication?

One strand of DNA serves as a template for the second strand to form

What do DNA polymerases require to initiate synthesis of a single strand of DNA?

RNA Primers

What are introns?

Some parts of the sequence that do not translate into proteins

What are exons?

The parts of the gene that encode mature mRNA

What is Alternative Splicing?

Exons are selectively included or excluded, resulting in several different sequence proteins from the same gene in an organism

Does DNA and RNA translation always code the same amino acid?

Yes, the code is universal

How do retoviruses differ in gene expression?

Retoviruses have information first transcribed into DNA

What are examples of Epigenetics?

Methylation of DNA or alternations to histones that DNA wraps around in cells

Are missense mutations negative or positive?

Both, mutation can be negative, neutral, or positive

What are examples of Biotechnology?

Electrophoresis, Polymerase Chain Reaction (PCR), Bacterial Transformation, DNA Sequencing

What is Electrophoresis?

Method used to separate molecules by size and charge. Used to separate DNA, RNA, or protein fragments to help scientists identify what molecules are present.

What is natural selections major effect?

Driver of evolution

What do all adaptations of life do?

Survival and reproduction

Define Differential Reproduction?

Process to cause competitions for resources and allow organism with desirable traits to reproduce

How do humans affect organisms survival?

Artifical Selection

What is Hardy-Weinberg?

Mathematical Equilibrium for how allici variations remain constant

How do scientist identify evolutionary relation?

Chart Fossil Evidences, DNA and Molecular Evidences, Moleculer and Cellular Features, Common Basis for Life, Lineage Tracking

How is phylogenetic tree useful?

Visually map out ancestorial relationships

How are new species arise?

Speciation

Define the Allopatric and Sympatric

Speciation when species are geographically isolated; species in same environment gaining preference for different resources

What is Punctuated Equilibrum?

Model where Species rapidly evolve

What is Extinction event driven by

Ecological Disturbances, Genetic Diversity Loss

What happened in Earths 4.6 Billion Years ago?

Formation of Earth due to High Temps and Asteroids

What experiment created life?

The Miller-Urey Experiment, create closed life with initial conditions

What is Oparin-Haldane

The Hypothosis stated inorganic molecules giving rise to life

How did amino acids arrive on Earth?

Amino Acids were found on meteoroids and brought to Earth