zo3 Flashcards
- specialized structures in cells that perform
specific functions - Ex. Nucleus, mitochondria, ribosomes, etc.
Organelles:
jelly-like substance that holds organelle
Cytoplasm:
what is the outermost component of a cell called?
- Functions:
- selective barrier
- encloses cytoplasm
- Extracellular: material outside cell
- Intracellular: material inside cell
Cell Membrane
Structure of Cell Membrane
- Called Fluid Mosaic Model
- Made of phospholipids and proteins
- Phospholipids form a double layer or bilayer
- Phospholipids contain 2 regions: polar and
nonpolar - Polar regions:
- “heads”
- hydrophilic (H2O loving)
- exposed to H2O
- Nonpolar regions:
- “tails”
- hydrophobic (H2O fearing)
- away from H2O
Structure of Cell Membrane
* Called Fluid Mosaic Model
* Made of phospholipids and proteins
* Phospholipids form a double layer or bilayer
* Phospholipids contain 2 regions: polar and
nonpolar
- Polar regions:
- “heads”
- hydrophilic (H2O loving)
- exposed to H2O
- Nonpolar regions:
- “tails”
- hydrophobic (H2O fearing)
- away from H2O
Ways molecules Pass through Cell Membrane
1. Directly through (diffusion):
O2 and CO2
(small molecules)
- Membrane channels:
- proteins that extend from one side of cell membrane to other
- size, shape, and charge (+/-) determine what can go through
- Ex. Na+ passes through Na+ channels
- Carrier molecules:
- bind to molecules, transport them across, and drop them off
- Ex. glucose - Vesicles:
- can transport a variety of materials
- fuse with cell membrane
Ways molecules Pass through Cell Membrane
1. Directly through (diffusion):
O2 and CO2
(small molecules)
- Membrane channels:
- proteins that extend from one side of cell membrane to other
- size, shape, and charge (+/-) determine what can go through
- Ex. Na+ passes through Na+ channels
- Carrier molecules:
- bind to molecules, transport them across, and drop them off
- Ex. glucose - Vesicles:
- can transport a variety of materials
- fuse with cell membrane
What is the movement of molecules from areas of high to low concentration called?
- Solution: solid, liquid, or gas that contains one or more solutes
- Solute: substance added to solvent that dissolves
- Solvent:
substance such as H2O that solute is being added to
Ex. Add salt to H2O. H2O =solvent, salt=solute, mixture=solution
Diffusion
- measures conc. difference at 2 points
- greater the distance the faster the solute
will travel
- Concentration gradient:
movement of fluid through a partition with holes
Filtration:
Mediated Transport Mechanisms
- diffusion with aid of a carrier molecule
- requires no ATP
Facilitated diffusion:
Mediated Transport Mechanisms
- moves substances from low to high conc.
- requires ATP
- Ex. Sodium-potassium pump
Active transport:
What is diffusion of water across a cell membrane called?
- _____
force required to prevent movement of water across
cell membrane
osmosis
osmotic pressure
Types of Osmotic Solutions
* ____ solution:
- lower conc. of solutes outside cell
- higher conc. of H2O outside cell
- H2O moves into cell
- lysis (burst)
Hypotonic
Types of Osmotic Solutions
- _____solution:
- higher conc. of solutes outside cell
- higher conc. H2O inside cell
- H2O moves out
- crenation (shrinks)
Hypertonic
Types of Osmotic Solutions
______solution:
- equal conc. of solutes
- water doesn’t move
- cell remains intact
Isotonic
What is the process that brings materials into cell using vesicles called?
- 2 types
-_____
cell eating (solid particles) - _____
cell drinking (liquid particles)
Endocytosis
Phagocytosis:
Pinocytosis:
- What is the process that carries materials out of cell using vesicles called?
Exocytosis
Cell Structures
* _____
Location: inside cell
Characteristic: jelly-like fluid
Function: give cell shape and hold organelles in
place
Cytoplasm
Cell Structures
______
Location: center of cell
Characteristic: all cells contain nucleus at some
point
Function: houses DNA
Nucleus
Cell Structures
*_____
Location: edge of nucleus
Nuclear envelope:
Cell Structures
______
Location: surface of nucleus
Function: where materials pass in and out of nucleus
Nuclear pores:
Cell Structures
_______
Location: inside nucleus
Characteristic: made of DNA and proteins
Function: part of genetic makeup
Chromosome:
Cell Structures
_____
Location: inside nucleus
Characteristic: loosely coiled chromosomes
Chromatin:
Cell Structures
____
Location: in nucleus
Function: produce ribosomes
Nucleolus
Cell Structures
______
Location: attached to RER or cytoplasm
Function: produce proteins
Ribosome
Cell Structures
_____
Location: cytoplasm
Characteristic: membranes with ribosomes attached
Function: site of protein synthesis
RER (Rough Endoplasmic Reticulum)
Cell Structures
______
Location: cytoplasm
Characteristic: membranes with no ribosomes
Function: site of lipid synthesis (Ex. Cholesterol)
SER (Smooth Endoplasmic Reticulum)
Cell Structures
_______
Location: cytoplasm
Characteristic: closely, packed stacks of
membranes
Function: collect, sort, package, and distribute proteins and lipids
- Golgi apparatus
Cell Structures
_______
Location: cytoplasm
Function: distributes materials out of cell
Secretory vesicle
Cell Structures
_______
Location: cytoplasm
Function: enzymes that digest foreign material
Lysosome
Cell Structures
______
Location: cytoplasm
Characteristic: contains folds (cristae)
Function: produces ATP
Mitochondria
Cell Structures
______
Location: cell surface
Characteristic: many per cell
Function: move materials across cell’s surface
Cilia
Cell Structures
_____
Location: cell surface
Characteristic: 1 per cell
Function: move cell, Ex. sperm
Flagella
Cell Structures
_____
Location: cell surface
Characteristic: shorter than cilia
Function: increase surface area
Microvilli
- What is it?
- cell’s framework
- made of proteins
- Functions:
- provide support
- hold organelles in place
- enable cell to change shape
Cytoskeleton
Types of Cytoskeleton
_____
- largest diameter
- provide structural support
- form cilia and flagella
Microtubules:
Types of Cytoskeleton
____
- medium diameter
- maintain cell shape
Intermediate filaments:
Types of Cytoskeleton
_____
smallest diameter
- involved in cell movement
- Microfilaments:
What is it?
- double helix in nucleus
- composed of nucleotides
- contains 5 carbon sugar (deoxyribose,
nitrogen base, phosphate
DNA
Flow of Genetic Information
* Also called _____
* Occurs in three stages:
– DNA replication
– Transcription
– Translation
Central Dogma
- What is it?
- information in DNA directs protein
synthesis - proteins provide code for _____
- enzymes regulate chemical reactions
- uses transcription and translation
Gene Expression
What is it?
- process by which DNA is “read”
- occurs in ribosomes
- produces mRNA (messenger RNA)
- mRNA contains codons
- codons: set of 3 nucleotide bases that code for a particular amino acid
Transcription
What is it?
- process by mRNA is converted into amino
acids (polypeptides)
- produces proteins
- codons pair with anticodons
- anticodons: 3 nucleotide bases carried by tRNA
Translation
What is it?
- formation of 2 daughter cells from a single parent cell
- uses mitosis and meiosis
- each cell (except sperm and egg) contains 46 chromosomes (diploid)
- sperm and egg contain 23 chromosomes
Cell Division
What is it?
- cell division that occurs in all cells except sex cells
- forms 2 daughter cells
Mitosis
Components of Mitosis
____
where 2 chromatids are connected
Centromere:
Components of Mitosis
2 strands of chromosomes that are genetically identical
Chromatid:
Components of Mitosis
____
small organelle composed of 9 triplets
Centrioles:
Stages in Mitosis
- time between cell divisions
- DNA is in strands (chromatin)
- DNA replication occurs
Interphase:
Stages in Mitosis
- chromatin condenses into chromosomes
- centrioles move to opposite ends
Prophase:
Stages in Mitosis
chromosomes align
Metaphase:
Stages in Mitosis
_____
- chromatids separate to form 2 sets of
chromosomes
- chromosomes move towards centrioles
Anaphase:
Stages in Mitosis
- chromosomes disperse
- nuclear envelopes and nucleoli form
- cytoplasm divides to form 2 cells
Telophase:
