Cell Bio Exam 1

Cells

the basic fundamental units from which living organisms are made

Cells are….

small, membrane-enclosed units that consist of an aqueous water based solution of atoms and organic/inorganic molecules.

Cells have what ability?

to create copies of themselves by growing and dividing into two

The simplest forms of life consist of how many cells?

a single cell

More advanced/higher organisms consist of

many cells

Cel biology is

the study of cell structure, physiological function, behavior, and interactions with one another and their surrounding environment.

Cells vary in

appearance and function

Smaller cells like…

bacterial cells

how small are bacterial cells

a few micrometers in length/diameter

human cells are typically how long

10-100 micrometers

What do many believe is the largest cell?

the ostrich egg

how small is the smallest object that the unaided human eye can see?

0.1 millimeters (100 micrometers) long.

Varying shapes of cells

round, oval, square, starfish-like, with and without protrusions, etc.

the shape can be…

uniform/regular or non-uniform/irregular

the shape of the cell can change based on the…

movement, location, and function.

Cells are diverse in their…

chemical requirements needed for survival and function

Some cells require…

oxygen, but for some it is lethal.

What other factors do cells need

air, water, and sunlight, others may need more complex molecules

What related to cells having different functions?

size, shape, and chemical requirements

Some cells function to produce…

various types of molecules

some cells perform…

mechanical work (muscle contractions, etc)

Some cells transport..

material or chemical signals from one part of the body to another.

Which organisms perform all of the functions of life?

The longest nerve cells are over

1 meter

The longest nerve cells can run from

axons

elongate region of nerve cell enabling the brain to send signals to distant parts of the body quickly

What is similar in cells even though their appearance and function vary?

the chemical make-up and they perform similar chemical functions/reactions

Central dogma

the overall process and molecules involved in the flow of genetic information is the same regardless of the cell/organism.

DNA is…

transcribed into (m)RNA

m(RNA)…

is translated into protein

What do all cells/living organisms use to make their DNA/RNA

the same 4 nucleotides

What varies in a DNA/RNA molecule?

how many of each nucleotide is present and their sequence or order of how they are linked together.

Each protein has a uniq

Genome

all of the DnA that makes up a cell

what does the genome include

the genetic program or blueprint for that cell and the whole organism

where did all the cells in your body ultimately originate from?

a single fertilized egg cell

what does the dna direct in a cell

the growth, development, and specificity of the cell through a process known as cellular differentiation

Different cells express…..combinations of genes

Where does our understanding of cell structure and function come from?

the invention of the microscope and technology

Who is considered to be the father of microscopy

anton van leeuwenhoek

Light microscope

uses visible light to illuminate specimens (can be living or dead)

Leewenhoek was the first to see and describe…

bacteria, yeast, the variety of life in a drop of water, and blood circulation in capillaries

Who is considered to be the English father of microscopy

Robert Hooke

What did Hooke reconfirm

Leeuwenhoek’s light microscope and improved upon its design

What term did Hooke coin?

cells

Where did the “cells” term come from?

the resemblance of plant cells to the rooms of where monks lived in a monastery

Who published that all plants are made of cells?

Matthias Schleiden, using the light microscope

who published in 1839 that all animals are made of cells?

Theodore Schwann, using the light microscope

Schwann and Schleiden’s findings…

ultimately formed the basis for the cell theory

The cell theory

all living cells are formed by the growth and the division of preexisting cells

What idea did Louis Pasteur rule out?

that organisms do not arise spontaneously, but are generated from preexisting organisms

Light Micrscope allows

us to see some basic (and larger) structures of cells

Why do we “stain” different parts of cells with color?

because they are transparent and it makes them easier to see with the microscope

Cell’s Outer boundary

consists of a cell wall and a plasma membrane

nucleus

a large, round structure containing all DNA

Transparent cytoplasm

surrounds the nucleus and fills the rest of the cell’s interior is the transparent cytoplasm

the light microscope can’t be used to distinguish…

objects that are smaller than half the wavelength of light, which is 0,2 micrometers

Electron microscopes

use beams of electrons instead of light as the source of illumination

how does the image on an electron-sensitive photographic plate form?

beams of fast-moving electrons are focused on a cell and are absorbed or scattered by the cell’s parts

Transmission electron microscope

a beam of electrons is used to visualize fine detail of the internal components of the cells

scanning electron microscope

electrons are scattered off the surface of cell to visualize cell surface detail

Who invented the electron microscope?

Max Knoll and Ernst Ruska in 1933

Most electron microscopes can “see” down to about

a nanometer

Although electron microscopes do not make atoms visible, they do allow…

individual molecules of biological importance to be distinguished

What can electron microscopes magnify?

objects up to one million to 100 million times

All electron microscopes suffer from a serious drawback

no living specimen can survive the electron beams, and thus they cannot show the movements that characterize a living cell

Prokaryotic

organisms made up of a single cell

examples of prokaryotic cells

bacteria, blue-green algae, and members of the domain archaea

Prokaryotic cells are

the most diverse and numerous organisms on the planet

Prokaryotic cells have

very simple cell structures

prokaryotic cells are characterized by

the absence of a distinct, membrane-bound nucleus, or membrane-bound organelles

DNA in prokaryotic cells

a single molecule found in circular form

Eukaryotic cells are

multi-cellular

Examples of eukaryotes

humans, animals, plants, fungi

single-celled organisms that are eukaryotic

yeast and protists (algae, paramecium, and molds)

Eukaryotes have a ….. cell structure that the prokaryotes

What characterizes eukaryotic cells?

the presence of a distinct, membrane-bound nucleous and membrane-bound organelles

DNA in eukaryotes

many of them in linear form

Eukaryotes are much …. than prokaryotes

Nucleus

location of DNA and chromosomes

job of the nucleus

information store of the cell

Nucleoli

found within the nucleus; location of ribosome synthesis

ribosomes

helps assemble polypeptides during protein synthesis

Mitochondria

site of ATP synthesis (chemical form of energy used by cells)

Chloroplasts

site of photosynthesis in plants and algae

Which contains their own DNA

Endoplasmic reticulum

makes and modifies newly synthesized Polypeptides and lipids for either secretion or for use inside of the cell

golgi apparatus

modifies polypeptides, and sorts and ships proteins and lipids for either secretion or for use inside of the cell

vesicles

functions such as transport, storage, and digestion

Lysosomes

break down molecules, foreign material and old damaged organelles

peroxisomes

break down toxic substances utilizing H2O2

transport vesicles

transport materials between organelles

Cytosol

the region within the plasma membrane that surrounds the organelles

cytoplasm refers to

the whole region of the plasma membrane

where do many of the chemical reactions occur?

in the cytosol

Cytoskeleton

confers shape to cells, aids in the internal organization of the cell, and allows for movement of cells and internal structures

All cells are thought to be descended from

a common ancestor

the knowledge gained from one organism contributes and may apply to…

our understanding of another organism

A model organism/system

typically a non-human species that is extensively studied to understand particular biological phenomena

The goal for discoveries made in the model organism/system will

provide insight into the workings of other organisms, such as ourselves