Biology Flashcards
What cells are ubiquitous plasmodesmata, making the entire organism a giant communication network?
PLANT CELLS
What is the name of cell-to-cell connections in animal cells?
GAP JUNCTIONS
A cell targeting itself
Autocrain
A cell targets a cell connected by gap junctions
singling across gap junctions
A cell targets a nearby cell
paracrine
A cell targets a distant cell through the bloodstream
Endocrine
What is the name of the signaling molecules used in endocrine signaling?
Hormones
How fast is endocrine signaling?
Relatively slow
What is the name of cell-to-cell connections in plant cells?
plasmodesmata
Signals that act locally between cells that are close together are called _____
signals.
paracrine
Which intracellular signaling molecule is used to activate protein kinase A (PKA)?
cAMP
Which of the following activates ERK?
EGF
Programmed cell death, or ______, removes damaged or unnecessary cells and plays a vital role in development, including morphogenesis of fingers and toes.
apoptosis
Which receptors typically play an important role in cell division?
Receptor tyrosine kinases
Change in the internal __________ is detected by receptors. These cells are stimulated when the level is too high or too low.
environment
Which of these are NOT a benefit of multiple negative feedback mechanisms?
Larger brain
Multiple negative ________ mechanisms provide a greater degree of control of the internal environment.
feedback
Change in the internal environment is detected by ________
. These cells are stimulated when the level is too high or too low.
rectpors
Where are changes (increase/decrease) in blood glucose levels detected?
pancreas
What is the effect of an increase in blood glucose concentration on the cells in the body?
water diffuses out
What is the process that converts glucose to glycogen in the liver cells called?
glycogenesis
High blood glucose concentration is detected by the ____
cells in the pancreas. The cells are located in the islets of _______
.
- beta
2. Longhans
What reaction takes place during glycogenolysis?
glycogen ——-> glucose
Positive feedback works in a feedback _____, where a small change is amplified into a ____ change. It is the opposite of ______ feedback, which maintains systems within narrow limits.
- Loop
- Big
- Negative
Which of the following is an example of positive feedback?
oxytocin triggering contractions
Which hormone controls the positive feedback loop involved in child birth?
oxytocin
Lipid that sits in the core of the membrane.
Cholesterol
The molecules that form a bilayer in membranes. The molecules are made from glycerol, two fatty acids and phosphate-linked head group.
Phospholipid
The structure that defines the borders of cells and most organelles.
Plasma membrane
What name is used to describe proteins that completely span the cell surface membrane?
integral
what are 3 components of phospholipids?
- fatty acids
- glycerol
- phosphate head
carbohydrates are always found on the exterior surface of cells and are bound either to proteins (forming ________ ) or to lipids (forming ______)
- glycoproteins
2. glycolipids
These carbohydrate chains may consist of 2–60 _______ units and can be either straight or branched.
monosaccharide
Along with ______ proteins, carbohydrates form specialized sites on the cell surface that allow cells to recognize each other.
peripheral
This recognition function is very important to cells, as it allows the _____ system to differentiate between body cells (called “self”) and foreign cells or tissues (called “non-self”).
immune
what 3 substances can diffuse across cell membranes?
- oxygen
- urea
- carbon dioxide
What do we call the net movement of particles from an area of high concentration to an area of lower concentration?
diffusion
Which two processes are involved in the active transport across membranes?
- _____ cytosis
- _____ cytosis
- endo
2. exo
What is the name given to the process where a cell engulfs a substance from its surroundings?
endocytosis
Roots of plants.
mineral ions
Guts of humans.
sugar
