Chapter 6-11 AP Biology

Mr. Davis's AP Biology

Metabolism

The totality of an organism’s chemical reactions.

Anabolic pathways

Consume energy to build complex molecules from simpler ones.

Catabolic pathways

Release energy by breaking down complex molecules into simpler compounds.

Second law of thermodynamics

Energy transfer or transformation increases the entropy of the universe.

Entropy

A measure of disorder, or randomness

Allosteric

When a protein’s function at one site is affected by the binding of a regulatory molecule to a separate site.

Free energy

The portion of a system’s energy that can perform work when temperature and pressure are uniform.

Enzymes can be effected by…

general environmental factors (temperature and pH) 75^o Celsius for bacteria and 37^o Celsius for humans

During glycolysis, for each mole of glucose oxidized to pyruvate

2 moles of ATP are used, 2 moles of ATP are produced

To sustain high rates of glycolysis under anarobic conditions, cell require

NAD+

What three pathways generate reduced electron carriers?

Citric Acid Cycle, Glycolysis, and Pyruvate Oxidation

Cell respiration equation

C₆H₁₂O₆ + 6O₂ →6CO₂ + 6H₂O + 36 ATP

Where does glycolysis occur?

Cytoplasm

ATP synthase at the inner mitochondrial membrane makes ATP and water, from ADP and phosphate, by coupling this to which other process?

Allowing H to move down its electrochemical gradient

Newborn mammals have a specialized organ called brown fat, where cells burn fat to CO₂ without capturing the energy to reduce electron carriers or drive ATP formation. How can this energy be used instead?

To generate heat

What is the purpose of fermentation reactions?

To regenerate NAD so glycolysis can continue

During intense exercise, muslces lack sufficient oxygen, so which process will these muslces mainly use?

Lactic acid fermentation

Overall equation of photosynthesis

Sunlight + 6H₂O + 6CO₂ → C₆H₁₂O₆ + 6O₂

Which two cellular organelles in eukaryotes have both electron transport systems and chemiosmotic mechanisms?

Chloroplasts and mitchondria

Chemiosmosis

A series of membrane-embedded electron carriers that ultimately create the hydrogen ion gradient to drive the synthesis of ATP.

Electron transport chain

The process by which a hydrogen ion gradient is used to produce ATP.

The citric acid cycle

The process by which the chemical breakdown of glucose is completed and carbon dioxide is produced.

Glycolysis

The process by which glucose is split into pyruvate.

Fermentation

A process that makes a small amount of ATP and can produce lactic acid as a by-product.

“Self feeders”

Autotrophs

Obtain organic material by the second major mode of nutrition, feeding.

Heterotroph

How oxygen enters into leaf cells

Stomata

In most plants, where the initial fixation of carbon occurs via Rubisco

C₃ Plants

Examples of these are sugarcane, corn, and grass.

C₄ Plants

How many “turns” of the Calvin cycle are required to produce one molecule of glucose?

6

Which of the following is mismatched with its location?

ATP synthesis - double membrane surrounding chloroplast

It occurs in the mitochondria

What is true about the Krebs cycle and the Calvin cycle?

They both are carried out by enzymes located within an organelle matrix

Cytokinesis begins during this final stage of mitosis

Telophase

Division of the cytoplasm of the cell

Cytokinesis

Sister chromatids begin to seperate

Anaphase

The genetic material of the cell replicates to prepare for division.

Interphase

Microtubules begin to attach to the centromeres of the sister chromatids.

Prometaphase

After which of the following checkpoints in the cell cycle is the cell first committed to divide?

• G₂

• M

• Interphase

• G₁

• MPF

G₁

If the S phase were eliminated from the cell cycle, the daughter cells would…

have half the genetic material found in the parent cell.

During mitosis, which of the following normally occurs?

Replicated chromosomes line up on the equatorial plate

What is the sequence of these events in meiosis?

A) Synapsis occurs

B) Crossing-over is completed

C) Condensation of chromosomes begins

D) Separation of homologous chromosomes begins

C, A, B, D

Condensation of chromosomes begins, synapsis occurs, crossing-over is completed, and separation of homologous chromosomes begins

A human cell in prophase of mitosis can be distinguished from a human cell in prophase 1 of meiosis by the presence of…

paired homologous chromosomes in the meiotic cell.

In most vertebrates, the sperm cell normally contributes what to the new organism?

A haploid complement of chromosomes

Why is it more practical to prepare karyotypes by viewing somatic diploid cells rather than haploid gametes?

Both sets of chromosomes, which are present in somatic diploid cells, need to be examined.

How and at what stage do chromosomes undergo independent assortment?

Meiosis I metaphase alignment

What allows sister chromatids to separate in which phase of meiosis?

Release of cohesin at centromeres in anaphase II

Crossing over begins to occur during

prophase I

Where X-shaped regions called chiasmata form for crossing over.

Prophase I

When sister chromatids that are no longer genetically identical are attached with microtubules and are arranged at the metaphase plate.

Metaphase II

Microtubules from one pole are attached to the kinetochore of one chromosome of each tetrad.

Metaphase I

Four daughter cells genetically distinct from each other and from the parent are formed.

Telophase II and cytokinesis

No chromosome replication occurs between the end of meiosis I and the beginning of meiosis II—formation of the cleavage furrow in animal cells.

telophase I and cytokinesis.