K324 Exam III

Where does glycolysis occur?

In the cytoplasm

Where does the Krebs cycle occur?

In the mitochondrial matrix

Where does oxidative phosphorylation occur?

In the inner mitochondrial membrane

In glycolysis, what is glucose broken down into?

2 pyruvate

In glycolysis, what is pyruvate broken down into?

2 NADH and 2 ATP

What are the four main types of glycolysis enzymes?

Kinase, Isomerase, Dehydrogenase, and Mutase

Where does anaerobic respiration occur?

In skeletal muscle cells and yeast

When pyruvate from glycolysis is moved into the mitochondria, what is produced?

CO2, NADH, and acetyl-CoA

Where are fatty acids degraded?

In the mitochondria

What is released with one round of the Krebs cycle?

2 CO2, 3 NADH, and 1 FADH2

What is FADH2?

An energy carrier molecule that holds reducing energy

What is glucose stored as in plants and animals?

Starch and glycogen, respectively.

What is another name for membrane transport that produces ATP?

Chemiosmotic coupling

Where are the most mitochondria found?

In cells that utilize a lot of energy → muscle, kidney, etc.

What kind of membrane structure do mitochondria have?

Double-membrane

What membrane has the highest protein content of any known membrane?

The inner mitochondrial membrane

What equation represents the proton motive force?

The Nernst equation

What is the name of the large protein complex that creates ATP?

ATP synthase

What is the percent efficiency of cell respiration?

\~50%

What electron carrier has the highest redox potential?

Oxygen

What kind of light does chlorophyll absorb?

Blue and red light

What reduction reaction happens in Photosystem I?

NADP+ → NADPH

Where does the ‘special pair’ chlorophyll receive their electrons from?

Water splitting in photosystem II

What is the most common protein on Earth?

Rubisco

Where is calcium stored for cell signaling?

The endoplasmic reticulum

Where are proteins made?

In the cytoplasm

What provides the energy for materials to move in and out of the nucleus?

GTP

What does the smooth endoplasmic reticulum do?

Creates lipids and releases calcium

What does the rough endoplasmic reticulum do?

Import proteins

What type of coat is formed during budding that drives vesicle formation?

Clathrin coat

What do vesicles use to recognize their target destination?

Snares

What holds misfolded proteins in the endoplasmic reticulum?

Chaperone proteins

Where are proteins processed in the Golgi apparatus?

The cisternae

What process imports fluid and cargo into the cell?

Endocytosis

What is the process of a cell engulfing large particles?

Phagocytosis

What is the role of lysosomes?

Cell degradation

What process destroys and recycles old organelles in the cell?

Autophagy

What molecules relay signals from GPCRs?

Trimeric GTP-binding proteins (G-proteins)

How many GPCRs are there in humans?

700+

What is produced when G-proteins stimulate adenylyl cyclase?

cAMP

What does cAMP induce?

Protein kinase A

What does Protein kinase A induce?

Gene expression

What is created from Phospholipase C activity?

Inositol 1,4,5-trisphosphate and diacylglycerol

What are Receptor Tyrosine Kinases (RTKs)?

Growth factor receptors

What do RTKs often induce?

Ras

What does activated Ras induce?

The MAP kinase cascade

What type of signaling is short distance and goes through extracellular fluid?

Paracrine

How do rapid signaling pathways mediate their signals?

Altered protein function

What types of filaments are polarized?

Microtubules and actin filaments

What is the major benefit of intermediate filaments?

They are able to withstand mechanical stress and have tensile strength

What is the assembly unit pf the intermediate filament?

The tetramer

What disease is associated with a defect in genes related to the nuclear lamina?

Progeria

What is the role of microtubules?

Organizing organelles in the cytoplasm

What is exposed at the minus and plus ends of microtubules?

Alpha and beta

What are the microtubule organizing centers?

Centrosomes

What GTP-driven process makes microtubules grow and shrink?

Dynamic instability

Kinesin and dynein are what kind of directors?

Plus end (kinesin) and minus end (dynein)

What are filopodia and lamellipodia?

Cell protrusions and sheets of membrane

What makes up microfibril?

Many repeating sarcomeres

What happens when the myosin heads bind to actin?

Phosphate release and the power stroke

What happens after muscle depolarization that causes contraction?

Calcium influx

Where does calcium bind in muscle contraction?

The troponin complex

What does troponin move?

The tropomyosin complex

What controls the progression through the cell cycle?

Cdks

What does the anaphase promoting complex (APC) induce the destruction of?

M and S cyclins during M phase

What does normally functioning p53 induce?

Apoptosis

What keeps sister chromatids together during DNA replication?

Cohesin rings

What phase does assembly of the mitotic spindle and contractile ring occur during?

M phase

What happens during anaphase A?

Chromosome are pulled poleward

What happens during Anaphase B?

Poles are pushed and pulled apart

When does the nuclear envelope reform?

During telophase

What gene is activated by survival factors to prevent apoptosis?

Bcl2 gene

What kind of cells does meiosis make?

Haploid

What structure is made by pairing of homologous chromosomes in meiosis?

A bivalent

What holds chromosomes together during recombination?

Chiasmata

What law is this: “alleles segregate independently and unite randomly” (?)

Mendel’s First Law: The Law of Segregation

What are the four types of tissues in animals?

Connective, epithelial, nervous, and muscular

What is connective tissue mostly composed of?

Collagen fibers

What links cells to the extracellular matrix?

Integrin adhesion

What molecules fill space in the extracellular matrix?

Proteoglycans and Glycosaminoglycans

What is the role of epithelial cells?

Separating biological compartments

Where do epithelial cells rest?

On a basal lamina

What is the role of tight junctions?

Preventing ions and solutes from leaking between cells

What are cadherins?

Molecules that create small links that are very strong in large patches

Where are adhesion molecules attached?

To the actin cytoskeleton via linker proteins

What is the role of desmosomes?

Joining the intermediate filaments in one cell to those in another cell

What are gap junctions?

Channel proteins that link with another cell

Where are intestinal stem cells located?

The base of the crypt

What is the role of hematopoietic stem cells (HSCs)?

Producing all blood cells

Embryonic stem cells can produce derivatives of all three germ layers, making them…?

Pluripotent

What type of genes have a gain of function relating to cancer?

Oncogenes

What type of cells have a loss of function relating to cancer?

Tumor suppressor genes

What is the final metabolite produced by glycolysis?

Pyruvate

What does the first step of glycolysis produce?

Glucose 6-phosphate

What does the electron transport chain convert high energy electron movements into?

Proton motive force

What complex are most chlorophyll molecules a part of?

The antenna complex

Where are proteins in the chloroplast synthesized?

The cytosol

What is the nucleotide bound by actin?

ATP/ADP

What is the nucleotide bound by tubulin?

GTP/GDP

What extracellular signals regulate commitment to the cell cycle?

Nutritional conditions and mitogens