Things I missed or need to preview before the Exam 1

Acrocentric

Refers to a chromosome with the centromere located near one end, resulting in one arm being significantly shorter than the other. These posses repetitive rRNA sequences on one end

NON- penetrating solutes for Tonicity

NaCl, KCL, CaCL2

Penetrating Solutes for Tonicity

Urea, glycerol, and glucose

Cyclin AMP and GMP

play crucial roles in cellular signaling pathways, acting as secondary messengers in various biochemical processes.

B-thalassemia

mutations in the B globin gene that generate additional splices

Limb Girdle Muscular Dystrophy

mutation in the calpain-3 gene that generates. new splice site with exon 16

miRNA

short, non-coding RNA molecules that regulate gene expression by binding to target mRNA and preventing translation.

snRNA

small nuclear RNA involved in splicing pre-mRNA by forming complexes with proteins to create spliceosomes.

RNA Polymerase I transcribes

rRNA which is a major component of ribosomes

RNA Polymerase II transcribes

mRNA, some snRNA and some miRNA

RNA Polymerase III transcribes

tRNA, some tRNA and some snRNA

Shape of Microtubules

The shape of microtubules is cylindrical, composed of tubulin protein dimers that assemble into hollow tubes. They play a critical role in maintaining cell structure and facilitating intracellular transport.

Gamma Tubulin in Microtublues

is a key protein involved in the nucleation of microtubules. It helps form the microtubule-organizing centers (MTOCs) and is essential for the proper assembly and stability of the microtubule structure.

What parts of the cytoskeleton undergo polymerization?

Microfilaments, microtubules, and intermediate filaments undergo polymerization, allowing for dynamic changes in cell shape and motility.

Cilia is a

microtubule

Shape of microfilaments

long, thin fibers that support cell structure and movement.

shape of intermediate filaments

fibers that provide structural support and strength in cells.

Dynenin motor proteins are more associated with what part of the cytoskeleton?

Cilia and flagella, enabling movement by facilitating transport along microtubules.

G1 phase

The first stage of interphase in the cell cycle, where the cell grows and prepares for DNA replication.

G2 Phase

The second stage of interphase in the cell cycle, where the cell continues to grow and prepares for mitosis by synthesizing proteins and organelles.

S phase

The synthesis phase of interphase in the cell cycle, where DNA is replicated to ensure each daughter cell receives the correct amount of genetic material.

M phase

The phase in the cell cycle where the cell undergoes mitosis, resulting in the division of the nucleus and cytoplasm, leading to the formation of two daughter cells.

G0 phase

A resting stage in the cell cycle where cells are not actively preparing to divide and can remain metabolically active but do not undergo cell division.

Order of the cell cycle

G1, G0, S, G2, and M phases

Aneuploidy

A genetic condition characterized by an abnormal number of chromosomes, resulting from nondisjunction during cell division.

Germline Mosaic

A genetic condition in which some of an individual's germ cells (sperm or eggs) are genetically different from the rest of their cells, potentially leading to inherited genetic disorders.

Mosacism

A genetic condition where an individual has two or more genetically distinct cell lines derived from a single zygote, leading to different characteristics in different tissues.

Gametes are

Haploid

Somatic cells are

diploid

Trisomy

Chromosome 47

Monosomy

Chromosome 45

Turner SYndrome

a condition caused by monosomy X, resulting in 45 chromosomes and affecting female development; Meiosis 1 or Meiosis II; female; infertility

Klinefelter syndrome

a condition caused by an extra X chromosome in males, resulting in 47 chromosomes; characterized by physical and developmental abnormalities, including infertility; 47, XXY; meiosis I or Meiosis II

Karyotype 47, XYY

MALE; nondisjunction in Meiosis 2 in dad

47, XXX

Female; nondisjunction in Meiosis 1 or 2; v2 in dad; 1 or 2 in mom; resulting in an extra X chromosome, which may cause mild developmental issues and infertility.

Mitotic Nondisjunction (post zygotic)

is the failure of chromosomes to separate properly during mitosis after fertilization, leading to cells with an abnormal number of chromosomes. This can result in mosaicism, where some cells have the normal karyotype while others have an altered one.

At the beginning of meiosis how many chromosomes and chromatids are there?

There are 46 chromosomes and 92 chromatids

At the END of meiosis, how many chromosomes ansd chromatids are there?

There are 23 chromosomes and 46 chromatids.

At the end of meiosis II, how many chromosomes and chromatids are there?

There are 23 chromosomes and 23 chromatids.

Interphase

The phase of the cell cycle during which the cell prepares for division, consisting of G1, S, and G2 phases, resulting in DNA replication and increased cellular components.

Metaphase

The stage of mitosis and meiosis where chromosomes line up along the cell's equatorial plane, ensuring proper segregation during cell division.

Anaphase

The stage of mitosis and meiosis where sister chromatids are pulled apart to opposite poles of the cell, ensuring each daughter cell receives an identical set of chromosomes.

Telophase

The final stage of mitosis and meiosis, where the chromosomes reach opposite poles of the cell, nucleus re-forms around each set of chromosomes, leading to the eventual separation of the daughter cells.

Cytokinesis

The process following telophase in cell division where the cytoplasm divides, resulting in two separate daughter cells.

chemotaxis

The movement of an organism or cell toward or away from a chemical stimulus, often seen in immune responses and cellular behavior.

Action Potential

The rapid change in membrane potential that occurs when a neuron sends a signal, characterized by a brief depolarization followed by repolarization.

Membrane potential

The difference in electric charge inside and outside of a cell, which is essential for the generation of action potentials and neuronal signaling.

Where is Glut 1

RBC; BBB

Function of GLUT 1

Where is GLUT 2?

Liver hepatocytes, Pancreatic B cells, Intestinal mucosal cells; Renal Tubules

For glut two, name the function of each: liver, Pan-B, RT, and Intestinal mucosal cells

Where is Glut 3?

Brain;

Function of Glut 3?

Where is Glut 4?

Adipose tissue, skeletal muscle, heart muscle

Function of Glut 4?

Wjere is Glut 5?

Spermatocytes

Function of glut 5?

Fructose transport

Types of Intermediate filaments

keratins, vimentin, neurofilaments, and desmin. They are essential for cellular integrity and resistance to mechanical stress.

Nucleation sites for microtubules

Gamma (γ) tubulin ring

complexes on the pericentriolar

material; Initiate microtubule formation

(polymerization)

centriole

A cylindrical structure composed of microtubules that forms the centrosome and plays a key role in cell division by organizing the mitotic spindle.

centrosome

the primary microtubule-organizing center in animal cells, important for the formation of the mitotic spindle during cell division.

centriole formation

9 sets of three (triplets) microtubules

arranged in a circular fashion; connected by MAP proteins

Basal Bodies

are cylindrical structures derived from centrioles, serving as the foundation for cilia and flagella assembly.

axoneme

the core structural component of cilia and flagella, consisting of a central pair of microtubules surrounded by nine doublet microtubules.

intermediate fillaments are

non polar

IF type 1

Acidic (I) and basic

(II) keratins;

Function and Location of Type 1 IF

Form complex network from nucleus to

plasma membrane in epithelial cells; Epithelial cells

The major component in skin cells and

hair

Function and Location of Type 3 IF

Desmin AND vimentin; primarily found in muscle and connective tissues, providing structural support.

Type 4 IF

Neurofilaments,

synemin, syncoilin

Function and Location of type 4 IF

Provide structural support in neurons; found in axons and glial cells.

Type 5 IF

Nuclear lamina

(lamins)

Nuclear lamina

A network of intermediate filaments providing structural support to the nucleus, composed of lamins. It plays a role in maintaining the shape of the nucleus and organizing chromatin.

Function and location of Type 5 IF

Provide structural support in the nucleus; primarily located in the nuclear envelope. (all nucleus of every cell)

Type 6 IF

Nestin

Function and location of type 6

Expressed mainly in the nerve cells and is

implicated in their growth; Angiogenesis and neuronal progenitor

cell marker

Free actin molecules in the cytoplasm

G-actin

Polymerized actin in a filament

F-actin

Terminal Web

Provides frameworks for the cell, attachment for

microvilli and basal bodies

Actin Toxins

Cytochalasins and Phalloidin

Cytochalasins (e.g. Aspergillus clavatus)

Block polymerization of actin'; Can be used to inhibit cell movement and division

& induce programmed cell death

Phalloidin (toxin found in Amanita phalloides)

Binds F-actin more tightly than G-actin

• Promotes excessive polymerization

and inhibits depolymerization

• Inhibits cell movement in vitro

MT toxins

Colchicine, Vinblastine/Vincristine, Paclitaxel (Taxol®)

Paclitaxel (Taxol®)

Stabilizes and prevents microtubule disassembly; arrests dividing cells in mitosis

Colchicine - treatment of gout

• Binds to unpolymerized tubulin molecules

• Prevents polymerization, prevents release of inflammatory initiators

Vinblastine and Vincristine

• Inhibit formation of mitotic spindle, inhibit uncontrolled cell division

Byproducts from Metabolism

lipofuschin, melanin, and hemosiderin

lipofuschin

Accumulation of oxidized lipids, phospholipids,

metals and other organic molecules as result of

lysosomal digestion

Accumulates over years (“wear & tear” pigment)

Melanin

Dark brown/brown/reddish pigment produced by

the oxidation of tyrosine

Melanocytes in the skin & responsible for color of

skin/hair pigmentation

Also produced by certain neurons of the brain

Hemosiderin

Iron-storage complex in cytoplasm

Due to phagocytosis of red blood cells

Mostly found in spleen

Simple cuboidal Epitheleum

Pseudoautosomal Dominance

Apparant autosomal inheritance (heterozygote and homozygote) of an autosomal recessive disorder have affected children

Halpoinsufficiency

Condition where a single copy of a gene is not sufficient to achieve a normal phenotype, often resulting in disease.

Dominant negative

A type of mutation where the altered gene product antagonizes the normal gene product, leading to a loss of function or abnormal phenotype.

What is better to have (these are in AD ONLY): Dominant Negative or Haploinsufficiency?

Haploinsufficiency is typically better

What is associated with micropinocytosis?

caveolins and flotillins

caveolins

are membrane proteins that play a critical role in the formation of caveolae, small invaginations in the plasma membrane involved in endocytosis and signal transduction.

flotillins

are a family of membrane-associated proteins that, like caveolins, are involved in the formation of membrane microdomains and play a role in endocytosis and cellular signaling.

dna replication

is the process by which a cell duplicates its DNA, ensuring that each new cell receives an identical copy of the genetic material, typically occurring during the S phase of the cell cycle.

steps in DNA replication

involves unwinding the DNA double helix, synthesizing new strands using DNA polymerase, and sealing the strands with DNA ligase to produce two identical DNA molecules.

DNA Gyrase

is an enzyme that alters the supercoiling of DNA, helping to relieve the strain generated ahead of the replication fork during DNA replication. It is a type of topoisomerase that introduces negative supercoils into DNA.