bio chap 3
list 4 organelles of the cell:
nucleus, cell membrane, centrioles, cytoskeleton
What is diffusion and osmosis?
molecules in a gas or liquid that move about randomly. the molecules collide with each other causing them to change direction. osmosis is the net diffusion of water across a selectively permeable membrane
Why can oxygen and carbon dioxide pass through the plasma membrane of a cell?
they can diffuse right through the lipid bilayer. they dissolve into the lipid bilayer, passing through like a ghost.they are called lipid-soluble molecules.
Gated channels are especially important in regulating the transport of what across a plasma membrane?
ions. which are, sodium, potassium, and calcium.
What does active transport require and in the presence of what?
it requires energy. active transport moves substances from an area of lower concentration to an area of higher concentration.
To move solutes like amino acids into a cell by active transport, the cell must do what?
What is endocytosis?
involves a membranous vesicle to move larger substances through the cell. it in moving those materials INTO the cell. there are three types, phagocytosis, pinocytosis, and receptor-mediated endocytosis.
Know what the sodium-potassium pump does.
it maintains the cells volume. it expels unwanted ions and keeps the needed ones.
Know what an isotonic solution is?
its when the extracellular and intracellular ionic concentrations are equal to maintain your cells. (9 grams of salt in one liter of solution)
In the cell, proteins that are synthesized for immediate use by the cell are normally produced where?
on free flowing ribosomes.
Which organelles produce proteins?
rough endoplasmic reticulum
What do lysosomes become after they have completed the digestion of cell parts?
The enzymes stored in peroxisomes are used to break down what?
toxic waste like hydrogen peroxide. they also destroy compounds that enter the cell like alcohol
To increase the surface area of some cells, the plasma membrane possesses what?
Muscle cells store energy in the form of what until it is used for the production of ATP?
What is metabolism in regards to the catabolic pathways.
metabolism is the sum of all of the chemical reactions in the organism. some of these chemical reactions are organized as metabolic pathways. (in patterns)
What is anabolic and catabolic pathways?
a specific type of metabolic pathway that forms a cycle in which substarte molecules enter and product molecules exit, this repeats the chemical cycle over and over again. they are two basic types of metabolic pathways.
the anabolic pathway-, molecules are assembled into larger molecules that contain more energy. (throwing up)
the catabolic pathway -larger molecules are broken down and releases energy.(throwing down.
ex: the assembly of a protein from many amino acids is an anabolic pathway
ex: the breakdown of glucose into water, carbon dioxide and energy is a catobolic pathway.
Cellular respiration is essential to eukaryotic cells because?
it removes electrons and hydrogen ions
Which stage in the catabolism of glucose involves the splitting of glucose into two three-carbon molecules?
Where in a typical human cell does glycolysis occur?
within the cells cytoplasm.
The two-carbon molecule acetyl is completely broken apart into carbon dioxide, hydrogen ions, and electrons in which process?
the preparatory step.
At the end of the electron transport system, oxygen combines with electrons and hydrogen ions to form what?
In the electron transport system, the energy used to synthesize ATP comes from the diffusion of what from the mitochondria?
What is used first by cells as an energy source immediately after a meal?
natural sugars (glucose)
Burning sensation associated with muscle fatigue is due to the accumulation of what?
The process by which embryonic cells go through functional and structural changes to become specialized is?
a process called differentiation
What step in the breakdown of glucose can occur without oxygen?
How does DNA differ from RNA?
DNA contains deoxyribose