15Chapter 3&4: Cells and Genetic function Flashcards
What are the 3 principle parts of a generalized cell?
- Plasma Membrane
- Organelles
- Cytoplasm
What are the two types of membrane proteins?
Integral and Peripheral Proteins
What is the difference between integral a and peripheral membrane proteins?
Integral proteins penetrate through the membrane.
Peripheral proteins are on the inner or outer surface.
List the functions of the cell membrane.
- Channel
- Transport
- Receptor
- Enzyme
- Anchor
- Identify marker.
What is the fluid on the inside of the cell called?
Intercellular Fluid
What is the fluid on the outside of the cell called?
Extracellular Fluid
Define the terms ‘active’ and ‘passive’ with respect to membrane transport.
Active Transport
- involves the movement of materials against the concentration gradient with the use of energy.
Passive Transport
- involves movement from a region of high concentration to a region of low without an expenditure of energy.
Osmosis
The diffusion of water molecules through a selective permeable membrane.
-it is the movement of water molecules (the solute) from an area of high concentration to an area of high concentration to an area of low concentration across the membrane.
Hypotonic
A lower concentration of solutes and a higher concentration of water occurs.
Hypertonic
A lower concentration of water and a higher concentration of solutes occurs.
What is the Cytosol of the cell?
- the intercellular fluid is the semifluid portion of cytoplasm.
- Made of 75-90% water, plus proteins, carbohydrates, lipids, and inorganic substances.
- Where many metabolic reactions occur.
Describe the structure of the nucleus.
A spherical structure surrounded by a double membrane, and contains the nucleolus and chromatin.
-includes nuclear envelope, nucleoli, and genetic material (DNA).
Structure and location of ribosomes.
- Tiny spheres that consist of ribosomal RNA and several ribosomal proteins.
- Occurs free (singly or in clusters) or together with endoplasmic reticulum.
- Sites of protein synthesis
What are the structure and function of lysosomes
structure: membrane-bound sacs with digestive enzymes, acid pH
function: -digests nutrients, phagocytized bacteria and old organelles (autophagy)
What is the function of the microtubules?
Help to determine cell shape and function in the intracellular transport of organelles and migration of chromosomes during cell divisions.
What is the primary function of cilia?
To move materials over the surface of cell located in the lining of resperatory tract and fallopian tube.
Cytoskeleton proteins with the smallest diameter are called _______.
Microfilaments
Transcription
The copying of a base sequence of DNA into a base sequence of RNA.
Translation
The use of the base sequence of mRNA to assemble the corresponding sequence of amino acids.
From DNA to RNA:
C-T-T-A-G-A-G-A-T-G
G-A-A-U-C-U-C-U-A-C
Cytokeleton
A network of several kinds of protein filaments that extend throughout the cytoplasm and provide a structural framework for the cell.
–consists of microfilaments, intermediate filaments and mircotubules.
The process of transcription provides which 3 types od RNA
- Messenger (mRNA)
- Ribosomal (rRNA)
- Transfer (tRNA)
Anticodon
A sequence of 3 nucleotides on a tRNA molecule;
which allows tRNA to bind to a specific sequence of 3 nucleotides on the mRNA.
A cell spends most of its life in what stage of the life cycle?
interphase
Mitosis
Division of the nucleus
Cytokinesis
Division of the cytoplasm
What is the function of a gene?
Determines the amino acid sequence of a protein.
Gene
A specific sequence of nucleotides in DNA.
Termination (stop) Codon
A 3 nucleotide sequence in mRNA that signifies the end of the message.
Which cell organelle is the site of fatty acid, phospholipid, and steroid synthesis?
Smooth Endoplasmic Reticulum
When equilibrium is obtained in diffusion, random moleculae motion continues but what stops?
Net Diffusion
Which lipids compose approximately 3/4 of the lipids in the plasma membrane of the human cell?
Phospholipids
The cellular contents located between the outer limiting membrane of the cell and its nucleus is/are collectively known as _______.
Cytoplasm
The only example of a flagellum in the human body is in the _______.
Tail of the sperm cell
Human cells are basically factories that provide large numbers of diverse what?
Proteins
In bulk-phase endosytosis, the cell membrane folds inward and forms a _________ vesicle, which allows a droplet of extracellular fluid to flow inward and then surround the liquid.
Pinocytic
In ______, pseudopods surround large, solid particles outside the cell and engulf them.
exocytosis
In metaphase, the centromeres of the chromatid pairs line up at what plane region?
Equatorial plane region
What happens to cells in hypotonic solutions?
Absorb water, swell and even burst
What happens to cell in isotonic solutions
No change
What happens to a cell in a hypertonic solution?
Loses waste and shrinks
What cell shape is best for diffusion?
squamous
What cell shape is best for communication?
stellate
What is the hydrophilic portion of the phospholipid bilayer made of?
phosphates
What is the hydrophobic portion of the phospholipid bilayer made of?
fatty acids
What are the 3 types of gated membrane channels?
- Ligand-regulated gated ion channels
- Voltage-regulated gates ion channels
- Mechanically regulated gated ion channels
What is the structure and function of the glycocalyx?
structure: -external to plasma membrane
- carbohydrate coat on the cell surface
- chemically unique in everyone
function: -immunity
- cell recognition and adhesion
What is the structure and function of microvilli?
structure: -extensions of the plasma membrane
- actin filaments at the base
function: -increases cells surface
- increases absorption
What is actin?
a protein that functions in movement
What is the structure and function of cilia?
structure: -hairlike projections (5x longer than microvilli)
- full of mircotubules
function: -move substances outside the cell
What are the 5 types of membrane transport?
- filtration
- simple diffusion
- osmosis
- carrier-mediated transport
- vesicular transport
What are the 3 types of carriers?
- uniport (1 solute at a time)
- symport (= or >2 in the same direction)
- antiport (= or >2 in different direction)
What is transcytosis?
in one side of the cell and out the other
What is exocytosis?
secretions of substance made in the cell.
What is the structure and function of both types of endoplasmic reticulum?
structure: membrane-bound, interconnected channels (cisterna)
function: Rough ER= (ribosomes)= protein and phospholipid synthesis
Smooth ER= steroid synthesis, detoxification, and calcium storage
What is the structure and function of the golgi complex?
structure: membrane-bound, flattened sacs
function: -carbohydrate synthesis
- modification of proteins
What is the structure and function of perioxisomes?
structure: membrane-bound sacs with free radical scavengers (H2O2)
functions: -neutralize free radicals
- detoxification of alcohol
- fatty acid hydrolysis
What is the structure and function of mitochondria?
structure: -membrane-bound
- linner membrane is highly convoluted (cristae)
function: -cellular respiration (glucose –> ATP)
What is the structure and function of centrioles?
structure: -cylinder of microtubules
function: -cell division
- forms the basal body of cilia
What is the building block of microfilaments?
Actin
What is the building block of intermediate filaments?
Keratin
What is the building block of microtubules?
Tubulin
What is the clear, structureless gel in a cell called?
Cytosol
What is a Na+-K+ pump?
A transmembrane protein
Cells specialized for absorption of matter from the ECF are likely to show an abundance of _______.
Microvilli
Aquaporins are transmembrane proteins that promote what?
Osmosis
Membrane carriers resemble enzymes except for what reason?
carriers do not chemically change their ligands
Where does the contrasport of glucose derive energy from?
a Na+ concentration gradient
What is the function of cAMP in a cell?
to activate kinases
What are most cellular membranes made by?
the endoplasmic reticulum
What is production of more than one phenotypic trait by a single gene called?
Pheiotropy
When a ribosome reads a codon on mRNA, it must bind to the _____ of a corresponding tRNA.
Anticodon
The normal functions of a liver cell- synthesizing proteins, detoxifying wastes, storing glycogen, and so forth- in what phase?
G phase
Genetic transcription is performed by ___________.
RNA polymerase
When does a chaperone come into play?
the folding of a new protein into its tertiary structure
An allele that is not phenotypically expressed in the presence of an alternative allele of the same gene is said to be __________.
Recessive
When do semiconservative replications occur?
the S phase of the cell cycle
What is the cytoplasmic division at the end of mitosis called?
cytokinesis
