Unit 12 Flashcards
What are the defining properties of stem cells?
unspecialized
perpetual self-renewal
ability to differentiate into a specialized cell
Types of stem cells from most unspecialized to specialized.
totipotent pluripotent multipotent omnipotent unipotent fully diffrentiated
Properties of totipotent cells
can self-renew by dividing
develop into early embryo and extraembryonic tissues (ex. placenta)
can differentiate into all the cells
EXAMPLE: cells in zygote in first few divisions
Properties of pluripotent cells
can self-renew by dividing
develop into the 3 primary germ layers of the embryo
can’t give rise to extraembryonic tissues
EXAMPLE: becomes any cell except extraembryonic tissues
Properties of multipotent cells
least plasticity
currently in us
can self-renew
develop into a limited number of specialized cells related to original tissue or organ
EXAMPLE: stem cells in bone marrow can differentiate into dif types of blood cells.
What is the epigenome?
The “layer” of chemicals on the nucleosome (DNA-histone complex)
What is acetylation?
Chemicals called acetyl groups attach to the histones causing the histones to loosen their grip on the DNA.
Increases transcription
What is methylation?
Chemicals called methyl groups attach to the histones causing the DNA to be tightly wound.
Decreases transcription
How do cells differentiate?
During different cell divisions, only certain parts of the genetic information is used.
Genes are turned on and off in a particular sequence
What is cell differentiation?
Cellular differentiation is the transformation of unspecialized cells called stem cells into specialized cells that carry out a particular task in the body.
What are tissues?
Collections of related cell types that work together to carry out a specific function
Explain muscle tissue
Contractile tissue
Produces movement of the body or its parts
Includes smooth, skeletal, and cardiac muscle
Explain epithelial tissue
Lining tissue
Covers the body and lines internal surfaces
Can be modified to perform specific roles
Explain nervous tissue
Receives and responds to stimuli
Makes up the structures of the nervous system
Regulates function of other tissues
Explain connective tissue
Supports, protects, and binds other tissues
Contains cells in an extracellular matrix
Can be hard or fluid
What does CRISPR stand for?
Clustered Regularly Interspaced Short Palindromic Repeats
What is CRISPR?
A process that allows scientists to utilize the CAS9 protein to find and remove a specific part of DNA using a template DNA strand
What is CRISPR used for?
It can be used to detect and destroy DNA to edit the genome.
What molecule is used to find a particular sequence of DNA?
an RNA sequence
What molecule is used to cut DNA?
CAS9 (enzyme)
Functions of pancreas
Make digestive juices / Produces enzymes that break down carbs, proteins, lipids, and nucleic acids
Produces hormones that regulate blood sugar levels
Produces sodium bicarbonate, a base that neutralizes stomach acid that allows enzymes to be effective
Function of liver in digestion
Produces bile, which is loaded with lipids and salts
Function of gallbladder
Stores bile
Functions of brain
Relay messages
Process / analyze information
Control almost all bodily functions
Positive feedback
The response strengthens the change in a controlled condition (enhances the change)
Negative feedback
The response reverses a change in a controlled condition (counteracts the change)
What organs make up the nervous system
Brain, spinal cord, peripheral nerves
3 types of neurons?
Sensory neurons
- Carry impulses from the sense organs to the spinal cord and brain
Motor neurons
- Carry impulses from the brain and the spinal cord to muscles and glands
Interneurons
- Connect sensory and motor neurons and carry impulses between them
What is action potential / nerve impulse?
reversal of charges
Explain the sodium-potassium pump and action potential
Outside is positive (NA+) and inside is negative (K+)
- bc of selective permeablity and active transport
Gates in NA+ channel open, letting NA+ in (action potential)
As action potential passes, gates in K+ channels open, allowing K+ to flow out, restoring neg potential
What are neurotransmitters?
Chemicals used by a neuron to transmit an impulse across a synapse to another cell
What organs make up the circulatory system?
Heart, blood vessels, and blood
Why is hemoglobin needed?
It binds oxygen and transports through tissues
Cells in blood and what they do?
Red blood cells: O2 transport
White blood cells: fight parasites/infection/bacteria
Platelets: clotting
Plasma in blood and what they do?
Albumins/globulins: substance transport
Fibrinogen: blood clotting protein
Pulmonary circulation vs systemic circulation
Pulmonary circulation moves blood between the heart and the lungs. It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide. The oxygenated blood then flows back to the heart.
Systemic circulation moves blood between the heart and the rest of the body.
Function of lymphatic system?
To collect and return fluid that leaks from blood vessels
Help absorb nutrients
Protect the body from disease
Destroy damaged red blood cells and platelets
What organs make up the respiratory system?
Lungs, nose, mouth, trachea, diaphragm, bronchi
What are alveoli?
Millions of tiny air sacs in lungs
Role of alveoli
Oxygen and CO2 exchange (gas exchange)
What organs make up the digestive system?
Mouth, esophagus, stomach, gallbladder, small intestine, large intestine
Accessory structures: salivary glands, pancreas, liver
What role does mouth play in digestion?
Mechanical digestion
Salivary glands release amylase to break down starches and release sugars
What role does esophagus play in digestion?
Has an epiglottis to prevent food from blocking air passageways
Performs peristalsis to squeeze “bolus” of food into stomach
Has a cardiac sphincter to close the esophagus after food has passed into the stomach and prevents the contents of the stomach from moving back up into the esophagus
What role does stomach play in digestion?
Mechanical/chemical digestion of food
Contractions through three smooth muscle layers for digestion
Acid production in the lining of the stomach which produces hydrochloric acid and mucus
Activates pepsin through the hydrochloric acid which work together to digest protein, chemical digestion of carbs is stopped because amylase cannot function in acidic environments and does not resume until the food passes into the small intestine
What role does small intestine play in digestion?
Most of the chemical digestion and absorption of food
Mixes chyme with the digestive fluids and enzymes from the pancreas, liver, and lining of the intestine
Villi and microvilli move provide surface area for nutrient absorption
Carbs and proteins are absorbed by villi capillaries
Undigested fat and fatty acids are absorbed by lymph vessels
What role does large intestine play in digestion?
Removes water from the undigested material that is left by absorbing it into the wall
Rich colonies of bacteria produce compounds that the body is able to use, like vitamin K
What does bile do?
Bile dissolves and disperses drops of fat and makes it easier to break them down
Which parts of the digestive system are involved in mechanical digestion?
Mouth, esophagus, stomach
Which parts of the digestive system are involved in chemical digestion?
Mouth, salivary glands, stomach, small intestine, large intestine, liver, gallbladder, pancreas
How is the structure of villi adapted to their function?
The folds and projections of the villi provide an enormous surface area for the absorption of nutrient molecules
What is the microbiome? What does it do for us?
The microbiome consists of diverse bacteria colonies, which can help produce compounds for the body to use, such as vitamin K
What organs make up the excretory system?
Skin, lungs, kidneys, ureters, urinary bladder, urethra
What role does skin play in excretion?
Excretes excess water, salts, and tiny amounts of urea
What role do the lungs play in excretion?
Excrete CO2
What role does the liver play in excretion?
Gathers excess amino acids from protein breakdown and converts them into useful compounds
This makes some nitrogen wastes in the process, which the liver converts into urea
What is urea?
Toxic waste produced when amino acids have been used for energy.
What role do the kidneys play in excretion?
Removes urea, excess water, and other waste products from waste-laden blood and passes them to the ureter
What role do the ureter play in excretion?
Carries urine to the urinary bladder from each kidney
What role does the urinary bladder play in excretion?
Saclike organ where urine is stored
What role does the urethra play in excretion?
Tube through which urine can be released
What are the 3 ways the kidney helps maintain homeostasis?
remove waste from blood
maintain blood pH
control H2O content (and therefore blood volume)
What is the functional unit of the kidney?
Nephron
What are the 2 processes involved in blood purification?
Filtration
Reabsorption
What kinds of material are filtered from the blood?
Water Urea Glucose Salts Amino acids Fats Some vitamins (excess)
What kinds of filtered materials are reabsorbed by the blood?
99% of water
Amino acids
Fats
Glucose
What is urine?
The material remaining after reabsorption
Comprised of urea, water, excess salts, and other substances
What is the difference between the superior vena cava and the inferior vena cava?
superior is from above
inferior is from below
What does septum do?
Separates the left ventricle (O2-rich blood) and the right ventricle (O2-poor blood)
