Cell Physiology Flashcards
What cells are used to measure other cells?
Erythrocytes due to their consistent size
What is a prokaryotic cell?
Bacteria and obscure microbes
What is a eukaryotic cell?
All other living things including humans
What do all human cells share?
Plamsa membrane
Nucleus
Numerous membranous organelles
What does the plasma membrane do?
Holds the cell contents inside
Regulates what comes in/out
Contains receptors, enzymes, and proteins
What is the structure of the plasma membrane?
phospholipid bilayer with proteins
What is the structure of the nucleus?
Large spherical in center of cell, outer border formed by nuclear membrane
What does the nucleus do?
Contains and protects the DNA
What is DNA’s usual form?
Chromatin
What is Chromatin?
Uncoiled DNA which cannot be seen with a normal microscope
What happens to DNA when a cell divides?
The DNA coils up into chromosomes
How many pairs of chromosomes do all humans cells have?
23 pairs
Why are the chromosomes paired?
They have instructions for the same thing, if one is damaged the other is used
What is the difference between X and Y chromosomes?
X chromosomes create a human, Y chromosomes simply direct it to make male structures
What are ribosomes?
The site of protein synthesis, made of protein and RNA and are either free in the cytoplasm or attached to the endoplasmic reticulum
What is the endoplasmic reticulum?
Network of highly folded membranes in the cell near the nucleus, makes membranes for the cell and synthesizes many other products
What are the two types of endoplasmic reticulum?
Rough ER
Smooth ER
What is Rough ER?
Has ribosomes, makes membranes that contain proteins
What is Smooth ER?
No ribosomes, makes membranes without proteins
What is the Golgi apparatus?
Flat stack of membranes, substances made by other organelles are sent to it where the it sorts, modifies, packages, and sends these substances to the proper location in the cell
What are Lysosomes?
Vesicles containing digestive enzymes
What do Lysosomes do?
Digest large molecules transported into the cell
What do mitochondria do?
Produce most of the cell’s ATP, four out of the five steps of cellular respiration occur here
What are centrioles?
Two cylinders made of tiny tubes, each cell has two
What do centrioles do?
They form the mitotic spindle that pulls chromosomes apart during cell division
What is the cytoskeleton?
Supporting framework of protein fibers inside of cells that helps maintain integrity and shape, also helps move things inside the cell
What does the cytoskeleton do for phagocytes?
Helps them move from place to place
What are flagella?
A single, long whip-like structure used for motility (Sperm)
What are cilia?
Numerous, short hair-like structures lining the inside fo tubes and help move things through them
What are the two major categories of cellular transport?
Passive
Active
What is passive transport?
Does not require any energy, move down concentration gradient
What is active transport?
Requires energy, move against concentration gradient, proteins required
What are the passive transport subtypes?
Simple Diffusion
Osmosis
Facilitated Diffusion
What are the active transport subtypes?
Endocytosis
Exocytosis
Active Transport
What is simple diffusion?
No protein carriers needed, substances simply move down the concentration gradient to be evenly dispersed
What is osmosis?
Simple diffusion of water, the water moves to reach equilibrium– when there is equal concentration in both areas
What is a solvent?
Liquid that dissolves a solute
What is a solute?
Substance dissolved in the solvent
What is a solution?
Solvent + Solute
What is a hypertonic solution?
More solute than water
What is a hypotonic solution?
Less solute than water
What is an isotonic solution?
Equal concentration of solute and water
What happens to cells in a hypertonic solution?
The cell will dehydrate as water leaves them to balance out the solution
What happens to cells in a hypotonic solution?
The cell will swell and burst (hemolysis of erythrocytes)
What is facilitated diffusion?
Passive transport that uses protein carriers, proteins create a bridge for substances
What is endocytosis?
Active transport that moves large substances into the cell, requires energy
What is exocytosis?
Active transport that moves large substances out of the cell
What is the cell cycle?
The life cycle of a cell from beginning until it divides
What makes up most of the cell cycle?
Non-dividing state
What is mitosis?
Division of the nucleus only, daughter cells are identical to the original and have the same number of chromosomes as the mother cell
Why do cells undergo mitosis?
Growth
Repair
Regeneration
What is meiosis?
Division of the nucleus only, daughter cells are genetically different from the mother cell and have half the chromosomes (23 unpaired), and the chromosomes are different
Why do cells undergo meiosis?
Sexual reproduction
What is cytokinesis?
Division of the entire cell after the nucleus divides
What is interphase?
The period of the cell cycle where the cell is not dividing, the DNA is in the form of chromatin
What is prophase?
The first phase, the nuclear membrane breaks down and chromatin coils into chromosomes, the mitotic spindle beings to form from the centrioles
What is metaphase?
The second phase, the chromosomes line up across the center of the cell (equator) where the protein fibers of the mitotic spindle attach to the chromosomes
What is anaphase?
The third phase, the sister chromatids of the replicated chromosome separate and the protein fibers of the mitotic spindle pull them to opposite sides of the cell
What is telophase?
The fourth phase, the chromosomes on the opposite sides of the cell revert back to chromatin and the nuclear membrane reforms. Then cytokinesis will then begin.
