Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/75

Click to flip

75 Cards in this Set

  • Front
  • Back
What are the Two types of Cells?
Sex Cells
Somatic Cells
What is a Somatic Cell?
All other cells in body minus the sex cells
Sex Cells
Germ or reproductive cells
Male- Spermatoza
Female- Oocytes
List the Cell Shapes
squamous
polygonal
cuboidal
columnar
spheroid
discoid
stellte
fusiform (spindle-shaped)
fibrous
What are teh Major constituents of the cell?
organelles
cytoskeleton
cytosol
What is the Cell Membrane?
The outermost layer of the cell
Functions of the Cell Membrane
isolate the cell
regulation of exchange (semi-permeable)
high sensitivity
structural support
Plasma Membrane
Oily film of lipids with diverse proteins embedded in it
Membrane lipids
Account for 42% of membrane mass
has a phospholipid bylayer
-hydrophobic and hydrophilic ends
Membrane Proteins
Account for 55% of membrane mass
Types of Membrane Proteins
Anchoring proteins
Recognition proteins
Enzymes
Receptor
Carrier
Channels
Anchoring proteins
attach membrane to other structures
Recognition proteins
identify cells as "normal" or "abnormal"
Enzymes
May be integral or peripheral, catalyze reactions
Receptor proteins
Sensitive to ligands, exposure to ligand = changes in cell activity
Carrier proteins
Binds solutes for transport across cell membrane
Channel (membrane protein)
permit H2O and ions to cross cell membrane
chemical, pressure, voltage
Membrane Carbohydrates
37% of mass
part of large molecules (glycoproteins)
form outer layer = glycocalyx
Glycocalyx Functions
1. lubrication and protection
2. Anchoring and locomotion- sticky
3. Specificity in Binding- function as receptors
4. Recognition- helps immune system determine between "foreign" and "self"
Microvili
extensions of membrane
Functions: increase surface area for absorption
-brush border
Cilia
Hairlike processes
-motile cilia, beat in waves, power strokes followed by recovery strokes
-help move a lot of stuff
Cystic Fibrosis
-Hereditary disease
-Chloride pumps fail to create adequate saline layer under mucous
Flagella
whip-like structure with axonene identical to cillium, but much longer than cillium
-Tail of sperm- only functional flagellum used for movement
Permeability
Determines which substances can leave and enter the cell
Impermeable
nothing can come in
Freely permeable
Eerything can come in
Selectively permeable
Only certain substances can come in
Passive Transport
Substance moves with out energy
Active Transport
Cell must use energy (ATP) to move substance
Difusion
Passive, random motion
Moves from high concentration to low concentration
Concentration Gradient
Difference in concentrations
Carrier mediated trasnport
Passive or active, requires certain integral proteins
Vesicular transport
Active transport, movement of materials in small membranous sacs (vesicles)
What influences diffusion?
Distance, molecule size, gradient size, electrical forces
Osmosis
diffusion of water
Occurs across selectively permeable membrane or freely permeable to water
Osmotic Pressure
Force of water moving into solution as a result of solute concentration
Hydrostatic pressure
Pushing agains a fluid (i.e. opposing osmotic pressure)
Osmolarity
Total solute gradiant ina solution
Tonicity
influence of osmotic solutions on cells
Isotonic
Osmotic flows of H2O in and out of cell, the solutions are equal in concentration gradiants
Hypertonic
Higher concentration of solute than cell (cell looses water)
Hypotonic
Lower Concentration of solute than cell (cell gains water from solution)
Functions of DNA
-Histone interaction
-DNA determines how we look
-DNA and histones determine information available to cell
What is the nucleosome?
DNA winds around histone
Chromatin
Loosely coiled nucleosomes (non-dividing cells)
Chromosomes
Tightly coiled nucleosomes (dividing cells)
How many pairs of chromosomes in a somatic cell?
23 pairs, 46 total
What pairs with Adenine?
Thymine
What pairs with Cytosine?
Guanine
What is a Gene
Funcitional unit of heredity passed down from parent to offspring
-Information containing segment of DNA that codes for a protein
What happens with GEne activation?
Gene is uncoiled, histones removed, bases read
Replicating DNA
-Transpcription
Messenger RNA is formed next to an activated gene (with an opposite code)
It then migrates to the cytoplasm
Replicating DNA
-Translation
mRNA code is "read" by ribosomal RNA as amino acids are assemebled into a protein molecule
-then the tRNA delivers the amino acids to the ribosome
Amino Acids
-3 bases code for one amino acid
Codons
-mirror image sequence in mRNA
-64 possible codons
-often 2-3 codons represent the same aminos acid
Start codon
AUG
3 stop codons
UAG
UGA
UAA
Mitosis
One cell divides into 2 daughter cells with identical copies of DNA
Functions of Mitosis
-Embrynic development
-Tissue Growth
-Replacement of dead cells
-Repair of injured tissues
Phases of mitosis
-prophase
-metaphase
-anaphase
-telophase
-cytokinesis
Prophase
-Chromosomes coil, each of 2 copies is a chromatid held to the other copy by centromere
-Centrioles move toward opposite ends of nucleus, spindel fibers (microtublules) appear between centrioles
Metaphase
Chromatids move to cneter of cell and line up

Meta=middle
Anaphase
Centomere of each chromatid pair splits
-daughter chromatids are pulled to opposite ends
Telophase
-Nuclear membranes of each cell re-form
-Nuclei enlarge and reappear
-Chromosomes uncoil
Cytokinesis
Cytoplasmic division of daughter cells
-start with one end up with two
Miotic Rate
-How fast mitosis occurs
-Rate of cell division
the longer cell's life, slower rate of division
Stem Cells
Maintain cell populations through repeated cycles of cell diision
Stem Cell functions
-One cell divides, one cell becomes specialized, one prepares for division again
-We can rapidly repair cells
-Embryonic stem cells- don't have a specific function yet
When do tumors form?
When rate of cell growth exceeds rate of death
Benign Tumor
remains within epithelium or connective tissue capsule
-stays contained
Malignant tumor
cells do not respond to normal control mechanisms
Primary Tumor
Tumor of origin (malignant)
Metastasis
Cells travel and establish secondary tumors (malingnant)
Modified Genes
Oncogenes
Causes of Cancer
Carcinogens
-Chemical
-Radiation
-Viruses