Cellular Foundations of Life Flashcards
Why is it important for a cell to have a semipermeable cell membrane?
The cell membrane is semipermeable to allow the cell to adapt to its environment, and also allows molecules to come in and out of the cell
What is the most important building block of a membrane?
The phospholipid bilayer
Which part of the cell is hydrophilic and faces the exterior and which part is hydrophobic and faces the interior?
the hydrophilic head is water loving and faces the outside of the membrane. The hydrophobic tails face the interior because they are fatty acids and dont like water
Are glycoproteins and glycolipids more likely located on the outer surface or the inner surface membrane?
outer surface
What is the function of the phospholipid bilayer membrane?
maintains structural integrity between inside and outside the cell
What role does cholesterol serve in a cell membrane?
maintaining membrane fluidity
oxygen is able to rapidly diffuse across cell membranes because its
small and nonpolar
simple diffusion of water is slower because it is
passive
facilitated diffusion allows water to cross membranes more quickly via
transmembrane and lipid-based
Steroid hormones like testosterone are large and need a transport protein to cross the cell membrane. This is because they are
nonpolar and lipid-based
simple and facilitated diffusion are examples of
passive transport
Which type of protein forms a pore that allows small molecules such as water to cross the membrane?
channel protein
how do carrier proteins work?
carrier proteins accept a molecule on one side of the cell, then the protein changes its shape as the molecule passes through the membrane, then releases the molecule on the membrane
what is the difference between active and passive transport?
passive transport does not require energy while active does
Why does the Na+/K+ pump require energy to operate and what provides this energy?
the pump requires energy because it is moving ions against their concentration gradient and the energy is provided by the hydrolysis of ATP
What specifically is the Na+/K+ pump moving in and out of the cell?
3 Na out and 2 K in
Cells require a different electrical charge across the inside and outside of their cell membrane. this differential charge is called the
resting membrane potential
the central dogma is the process whereby
DNA makes RNA makes protein
what are transcription factors?
proteins
what do transcription factors do?
essential for gene expression and transcription
what organelle is responsible for making proteins
ribosome
the majority of cells in the pancreas have abundant rough ER. what is the most likely primary function of a cell with abundant rough ER?
protein production and secretion
A cell has abundant smooth ER. What is the most likely function of a cell with abundant smooth ER?
synthesis of lipids for steroid hormone production
Why are ribosome clinically important?
ribosomes are a target of many antibacterial drugs
Sodium and potassium are important electrolytes in the body. What are the 2 ways that they can cross the cells membrane to enter a cell?
sodium/potassium pumps and ion channels
which components are the main facilitators of transport across the cell membrane?
proteins
Oxygen therapy is often provided to animals that are having difficulty breathing. Inhaled oxygen is quickly absorbed from an animal’s lungs into the blood stream. This is because it can easily diffuse down its concentration gradient. Why can oxygen easily diffuse across the cell membrane?
it is small and non-polar
what term best describes the process of making mRNA from DNA?
transcription
which organelle is responsible for breaking down and recycling aged cellular components?
lysosome
Plasma cells are a type of white blood cell that can be identified by the position of their nucleus, which is usually pushed to one side rather than being centrally located. Plasma cells are also recognizable because of the pale zone around their nucleus, which is known as the ‘perinuclear halo’ (black arrow). Which organelle creates the effect of the perinuclear halo?
the golgi apparatus, which is packaging proteins
