Chapter 7 - Cell Structure Flashcards
If a microscope eyepiece is marked x10 and the objective lens is marked at x20, what is the total magnification?
X200
Name the two types of microscopes
Compound microscope
Electron microscope
What is a compound microscope used for?
It shows a general overview of the cell
Can only identify: the nucleus, cell membrane, cell wall, cytoplasm, vacuole, chloroplasts
What is an electron microscope used for?
Allows to see the ultra structure of a cell
Uses a beam of electrons instead of a light
Gives a magnification of x250,000 and higher
What are the two types of electron microscope?
T.E.M (transmission electron microscope) - shows the internal structure of a cell
S.E.M (scanning electron microscope) - provides surface views
What are plant cell walls made of?
Cellulose
The details of a cell as seen using an electron microscope are known as the cell….
Ultrastructure
What are cell membranes made of?
Phospholipids and proteins
What is an ultra structure?
Fine details of a cell as seen with an electron microscope
We can see the organelles of a cell
What are organelles
Cell component that performs a specific function for a cell
Describe a cell membrane
Composed of phospholipids and proteins
Retains the cells contents
Controls what passes in and out of a cell (semi-permeable)
Supports the cell
What is a phospholipid made up of?
Lipids and phosphates
Lipids hate water, they look like the tail
Phosphates love water, looks like the head
What is cytoplasm?
Jelly like fluid that holds the organelles in place
Describe the nucleus.
Surrounded by a double membrane with nuclear pores
Allows entry and exit to molecules
Contains chromosomes
Controls the cell
What are chromosomes?
DNA - deoxyribonucleic acid
The cells genetic formation
What is the nucleolus?
A dark structure in the nucleus
Contains RNA, DNA and proteins
Makes ribosomes
What is chromatin?
Describes chromosomes when they are not needed for dividing
It’s the liquid form of dna
What is the mitochondrion?
It supplies energy to the cell when respiration takes place
Cells with a lot of mitochondrion create a lot of energy
Describe ribosomes
Tiny, bead like structures made of dna and protein
Makes proteins by combining amino acids
What are chloroplasts?
Green structures in plant cells
Green because of the pigment chlorophyll
Photosynthesis takes place here
What is a cell wall and it’s functions?
Made of cellulose and fully permeable
To support and strengthen the plant cell
What is the vacuole?
A place where plants store the food they produce
Strengthens the cell
Name 3 differences between a plant and animal cell
Animal cell. Plant cell
No cell wall Cell wall
No chloroplasts Contains chloroplasts
Small vacuole. Have large vacuoles
What is a eukaryote?
An organism whose cell contains a nucleus and other membrane bound organelles
E.g. animals, plants, fungi
What is a prokaryote?
An organism whose cell doesn’t have a nucleus or any other membrane bound organelles
E.g. bacteria
Name an example of animal cell that contains made mitochondrion
Muscle cell
Function of a ribosome
To manufacture proteins
What is responsible for photosynthesis?
Chloroplasts
Function of the eyepiece.
Enlarges or magnifies the image
Function of the nosepiece.
Revolves to allow an objective lens to be used.
Function of the objective lens.
Enlarges or magnifies the image
Function of the focus knobs
Allow a clear image to be seen
Function of the stage
Holds the microscope slide in place with clips.
Function of the diaphragm of a microscope.
Adjusts the amount of light passing through the slide.
Function of a mirror
Reflects light that passes through the slide.
What stain is used to examine a plant cell?
Iodine
What stain is used to examine an animal cell?
Methylene blue
What is a phospholipid?
It is composed of a lipid group and a phosphate group with proteins embedded.
All membranes are made up of a double layer of phospholipid
What’s the functions of a membrane?
Retains liquid contents
Controls what passes through them.
Recognition of molecules (one molecule can attach to another molecule that is of similar shape)
What are plastids?
They are found only in plant cells.
They include: chloroplasts (where photosynthesis takes place), chromoplasts (brightly coloured structure that turns into a chloroplast), leucoplasts (colourless plastids that store starch)
What is the protoplasm?
The protoplasm is all the living parts of a cell
