Bio 1A 27-31

Why was a C.elegans used as a model organism? Who used them?

-959 somatic cells so linage of cells is mapped to it is easy to follow -transparent -Sydney Brenner

Epithelial tissue form and function

-Epithelial tissue covers the outside of the body and lines the organs and cavities within the body -it contains cells that are closely joined-forming a barrier -it is polarized-apical surface faces lumen and is therefore exposed to air and fluid -regulates exchange of materials

What do multi-step pathways allow for?

-Provide control points for further regulation -coordination with other signals -termination of the signal

Connective tissue form and function

-mainly binds and supports other tissues -contains sparsely packed cells scattered throughout an extracellular matrix (fibers made of proteins) -contains cells, including fibroblasts and macrophages -examples-tendons ,ligament, bone, adipose, blood, and cartilage

4 steps of a insulin receptor as a receptor tyrosin kinase?

1. Insulin binds receptor 2. Receptor autophosphorylates itself 3. Insulin response protein is phosphorylated, an activate glycogen synthase 4. glycogen synthase converts glucose into glycogen

What are the 3 molecular interactions an egg has with a sperm during fertilization?

1. sperm penetrate the protective layer around the egg 2. receptors on the egg bind to proteins on the sperm. This is done through contact dependent signaling 3. Changes at the egg surface precent polyspermy, the entry of multiple sperm nuclei into the egg

How many cell types does the human body contain?

210

What is a hox gene?

A cluster of genes that is in the order of the representation of the animal. like reading a book left to right, nose to tail

nerous system

A complex system of nerves that allow one to register touch, move, breathe, feel and think. There are two types: Peripheral and Central. brain, spinal cord, nerves, and sensory organs

What does a generic signal transduction look like?

A generic signal transduction starts with a ligand (signal molecule) which binds to a receptor proteins and, these two things then go through a ligand-receptor interaction which initiates the process of signal transduction

Each taste bud has what?

A hetergenous variation of all the different taste sensations- sweet, salty, sour, butter, and umami

How do GTP-binding proteins work? (G-proteins)

A signal transduction occurs which causes a signal to turn on. This causes the GDP in the G-protein complex to be switched with a GTP turning the complex on which releases a signal. In order to remove the GTP, hydrolysis needs to occur which turns the G-protein off and releases a phosphate

Once the acrosomal process occurs what happens after?

After the acrosomal process the ligand from the sperm can bind to the receptor on the egg which initiates signaling

muscular system

Allows manipulation of the environment, locomotion, and facial expression. Maintains posture, and produces heat. skeletal muscles

What is an acrosome? Why is it important? How is it done?

An acrosome is an organelle at the tip of the sperm releases hydrolytic enzymes that digest material surrounding the egg This is done b/c acrosomes are packets of hydrolytic enzymes that dissolve the outer jelly of the egg It is important in order to break through the egg

digestive system

Breaks down food into absorbable units that enter the blood for distribution to body cells. mouth, pharynx, esophagus, stomach, intestines, liver, pancreas, anus

What is differentiation?

Cells become specialized in structure and function

How does the dorsal lip produce chemical signals that bind to receptors on ectodermal cells that determine their fate?

Done through a receptor tyrosine kinase system, with BMP being the signaling molecule which binds to a receptor tyrosine kinase, phosphorylation of proteins occursm where it is translocated to the nucleus where is acts as a transcription factor causes gene expression

How does EGF work, what does it do?

EGF works when an anchor cell secretes inducer that influences cell fate, the anchor cell also scretes EGF, which activates EGF receptor, leading to high EGF promoting cell type 1 fate. In contrast, low EGF promotes cell type 2 fate No EGF promotes cell type 3 fate

What are the three germ layers called from the gastrulation and what they do.

Ectoderm is the epidermis (skin and sweat glands) and nervous system Mesoderm is the connective tissue, skeleton, muscle, blood, and blood vessels Endoderm is the gut

How does GPCR signaling through G proteins work?

First the G protein needs to be activated with a signal. This is done by a ligand activating the GPCR which then activates the G protein changing the GDP to GTP. This active form can interact with other proteins. When the ligand is removed from the GPCR the G protein is hydrolysised an returns to its inactive form and this process can then be repeated with a new ligand

How does bitter taste get recognized?

GPCR is activated by a ligand (bitter in this case). G-protein is activated and splits into the GTP+alpha and the Beta+gamma. This beta and gamma sub units activates phospholipase c which lead to the hydrolysis PIP2 forming IP3 and DAG. The IP3 is important as it activates specific IP3 receptors allowing for calcium ions to lead to endoplasmic reticulum. The calcium increases intercellular Ca2+ concentration and activates the sodium selective channels (TRPM4/5), and then the PANx1 is actiavted produces ATP which is used as a neurotransmitter

How many transmembrane domains does a GPCR have?

Has seven transmembrane domains, the in cell part of the domains interacts with the G protein

What did Richard test?

He tested children who had incomplete neural tube closer -gave women folic acid to help neural tube closer of children

What are the stages of food processing?

Ingestion, Digestion, absorption, elimination

How to identify genes involved in cell determination?

Isolate the mutant, map and sequence of mutated genes, and identify growth factor and receptor

What binds more preferable to a GTP-binding protein, GDP or GTP?

It perfers GTP in comparison to GDP b/c there is more GTP in the cell

Examples of essential nutrients

Linoleic acid is an essential fatty acid, which goes thorugh fatty acid desaturase and becomes y-linoleic acid which is needed to make essential nutrients

positive and negative feedback loops

Positive feedback loops enhance or amplify changes; this tends to move a system away from its equilibrium state and make it more unstable. Negative feedbacks tend to dampen or buffer changes; this tends to hold a system to some equilibrium state making it more stable.

skeletal system

Protects and supports body organs and provides a framework the muscles use to support movement. Made up of bones and joints

Who discovered signaling molecules that control cell detremination and growth? How was it done?

Rita Montalcini and Stanly Cohen discovered by using nerve growth factors. they placed a cluster of neurons from a chick in a culture dish, added tumor cells and show an outgrowth of neurons

When sperm binds to an egg what cascade of events occurs?

Signaling molecules on sperm binds receptor on oocyte, which signlas PLC to cleaves a phospholipid becoming PIP2 and then becoming IP3 and DAG. IP3 is a second messenger that binds to a receptor of the ER and leads to the release of calcium, while DAG is a second messanger that activates protein kinase C

What is cell lineage?

The developmental history of individual cells from their ancestral cells (precursor/progenitor) to their ultimate.

What is morphogenesis?

The regulation of the pattern of anatomical development

What is epidemiology?

The study of human health and disease in populations

What did Spemann and Mangold do?

They discovered tat signals are responsible for specifying the nervous system from ectoderm. They did this by transplanting tissue from the dorsal lip of the blastopore from a pigmented embryo into the ventral region of anon pigmented embryo. Where the second tissue was planted a second neural section was created

How are stem cells used for diabetes?

Transplantation of Beta stem cells allows for a diabetic to monitor glucose levels naturally

circulatory system

Transports oxygen, waste, nutrients, hormones, heat, etc... around the body heart, blood vessels, blood

What is the blastula?

a ball of cells with a fluid-filled cavity called a blastocoel

What is endocrine signaling?

a cell targets a distant cell through the bloodstream example hormones go from an endocrine cell, travel through the bloodstream, and reach their target cell

What is cleavage?

a period of rapid cell division without growth

Organs level of organization

a structure of 2 or more tissue types performing a specific physiological function

What is homeostasis and how does it perform?

ability of body to maintain steady state physiological conditions. negative and positive feedback loop

EGFR is a system that does what?

activates many signaling cascades. EGF is the ligand in this situation

What is genomic equivalence?

all cells in the body derive from a single cell and have the same genetic material

What are teratogens?

anything that causes patterning mutations example corn lily causes a cyclops sheep can cause developmental issues in humans

What are the 5 vital organs

brain, heart, liver, lungs, kidney

What is paracrine signaling?

cell signals nearby cell

Cells function in organization

cellular processes specialized to perform the tasks required of a given physiological system

What happens during digestion?

chemical digestion (enzymatic hydrolysis) where more complex carbs are broken down

formation of connective tissue

collagen fibers linking fibroblast together to form connective tissue

Tissues function in organization?

collection of cells that perfor similar functions that are held together by extracellular material and cell-cell junctions (proteins connections)

Endocrine system

coordination of body activities (such as digestion and metabolism) pituitary, thyroid, pancreas, adrenal, and other hormone-secreting glands

What are organs composed of?

different layers of tissue

excretory system

disposal of metabolic waste, regulates osmotic balance of blood kidneys, ureters, urinary bladder, urethra

Difference between endocrine and nervous system

endocrine as longer lasting effects, nerve signals are very fast and don't last long

What is development and what are the 4 subprocesses?

events in changing from simple to a more complex form. The four subprocesses are cell division, differentiation, morphogenesis, and pattern formation

What are fibroblast, and what are they can example of?

fibroblast make cell matrixes like collagen, connective tissue, and they provide structure for the cells to interact

Many taste receptors use the mechanism of GPCRs where what is the ligand?

food is the ligand

What is neurulation?

formation of neural tubes

smooth muscle function

forms walls of organ and surround blood vessels. involuntary movement

What is fertilization?

fusion of male and female gametes to form a zygote

After the ligand of sperm binds to the receptor what happens?

fussion of the sperm and the egg occurs

What is ectothermic

gain heat from external sources -most invertebrates, fishes , amphibians, and non-avian reptiles -tolerate greater variation in internal temperature

What is endothermic

generate heat by metabolism -birds and mammals -active at a greater range of external temperatures

What is a pluriopotent stem cell?

give rise to all cells that exits in the adult, an example is embryonic stem cells which are pluripotent

What is a multipotent stem cell?

give rise to limited number of cells, an example is adult stem cells which are multipotent, example bone marrow can only form blood cells

What is a unipotent stem cell?

give rise to only a single cell type

In the insulin receptor system what enzyme is important?

glycogen synthase, which takes glucose and makes glycogen polymers

What is Doug Melton trying to do?

goal is to take stem cells into insulin producing cells for diabetes.

Organ system levels of organization

group of organs that work together to perform a specific function 11-nervous, muscular, endocrine, circulatory, excretory, digestive, respiratory, immune, skeletal, integumentary, reproductive

What does the dorsal lip do?

holds chemical inducers that initiate cell fate

What are exchange surfaces?

internal, yet connected to the outside environment highly branched to maximize surface area examples-lining of small intestines, lung tissue, blood vessels in kidney

What is synaptic signaling?

involves neurons secreting neurotransmitters across a synapse to target cells

What is morphogenesis? Its correlation to a blastula to 3 germ layers?

is the generation of ordered form and structure. Gastrulation is when the embryo acquires 3 germ layers via extensive cell movements and rearrangements

What did a mutation in hox genes lead to?

led to the appearance of entire body part in the wrong location

What is contact-dependent signaling?

membrane-bound signals bind to receptors on adjacent cells

examples of positive and negative feedback loops

negative -body temperature and sweat positive- uterine stretching and oxytocin release

What is nervous tissue comprised of? Functions?

neurons and glial cells -sensory input -control muscles and glands -homeostasis -mental activity

Are taste receptors only found on the tongue?

no also found in other organs like the pancreas

Where does gasturaltion occur in the bundle of cells

occurs at the dorsal lip of the blastopore

What is cell determination? What molecular systems determine a cells fate?

potential fates become more limited until a cell is committed to its final cell type differential inheritance of cytoplasmic determinants and cell-cell communication(this should remind u of 4 things)

What are blastomeres?

progressively smaller cells produced by cleavage

What needs to be done in order to turn off a RTK?

protain phosphatase removes a phosphate which turns off the system

integumentary system

protection against mechanical injury, infection, dehydration, and thermoregulation skin, hair, claws, skin glands

Immune/Lymphatic System

protects the body from disease bone marrow, lymph nodes, thymus, spleen, lymph vessels

Cardic muscle function

pumps blood through the body. involuntary movement. Is a specialized muscle

Reproductive system

reproduction ovaries, testes

Why do embryos look similar in the beginning?

shared features in the beginning has similar cell signaling and shared evolutionary pattern

3 types of muscle tissue

skeletal, cardiac, smooth

What provides "power" to the tail of sperm?

sperm tails are structural motors powered by mitochondria energy

Steps of cell signaling via receptor tyrosine kinases

step 1) ligand binds to the binding site on both RTK's and this causes dimerization (they come together) step 2) 6 ATP phosporylate the Activated TRK step 3) relay proteins with unique formation can then create varying cellular responses

human body anatomical stance

stomach=ventral back=dorsal head=anterior feet=posterior transverse= right to left

After fusion of sperm and egg, what happens

the cortical reaction occurs which makes sure polyspermy doesn't occur. This is done by sending a wave of calcium throughout the cell

respiratory system

the system of organs involved in the intake and exchange of oxygen and carbon dioxide between an organism and the enviornment lungs, trachea

What are stem cells?

undifferentiated cells that can be come differentiated cells

What are the essential nutrients that an animal needs?

vitamins, minerals, fatty acids, amino acids

Skeletal muscle function?

voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control

What is intracellular fluid? What is extracellular fluid?

water and dissolved ions inside of cells=cytosol interstitial fluid + blood allowing for exchange of varying things across cells