Biology FOUNDATIONS IN BIOLOGY

Microscopy magnification more microscopy eukaryotic cell structure ultrastructure of plants cells prokaryotic and eukaryotic cells

What is pili

faint strands of proteins

what is the function of the slime capsule in a prokaryotic cell

helps protects bacteria from phagocytosis by a white blood cell

what is plasma cell membrane made from

made from proteins and lipids

what is the plasma cell membrane function

regulates movements of substances inside and out of cell

function of smooth endoplasmic recticulum

synthesises and processes of lipids metabolism of carbohydrates detoxifying harmful

function of rough endoplasmic reticulum

folds and processes proteins that have been made at ribosomes

how is the order of amino acid determined

the DNA sequence of the gene

how are proteins formed

by joining amino acids together in a specific order

function of a nucleus

contains genetic information and controls all metabolic activities

how do scanning electron microscopes work

1. electron gun produces a beam of electrons that pass down the microscopes

2.inside the SEM is a vacuum so the electrons can pass through without bouncing of molecules in the air

3. electrons are scattered from the surface of the specimen and detected and 3D image is produced

4. final image is produced on fluorescent screen

how does transmission electron microscopes work

1. electron gun produces a beam of electrons that pass down the microscopes

2.inside the SEM is a vacuum so the electrons can pass through without bouncing of molecules in the air

3. specimen is placed in a path of an electron beam and some electrons pass through and a 2D image is produced

steps of protein synthesis for protein that stay inside the cell (Do Messy Ribbons Fold)

(D) - DNA sequence of the gene is copied into mRNA (M) - mRNA passes through a nuclear pore & into cytoplasm (R) - Free ribosomes bind to mRNA and read the mRNA sequence and assemble amino acids into a polypeptide chain (F) Protein is released into cytoplasm where it folds and can carry out its role

steps to protein synthesis for proteins that are secreted from the cell (Daring Messengers Roughly Transport Vessels Outside)

(D) - DNA sequence is copied into mRNA (M) - mRNA leaves the nucleus via the nuclear pores and into the cytoplasm (R) - Ribosomes on the surface of the Rough Endoplasmic Recticulum (RER) translate the mRNA to a polypeptide chain (T) - The polypeptide is packaged into a vesicle and transported to the golgi apparatus (V) - The Golgi apparatus packages and modifies the protein into a new vesicle for secretion (O) - Vesicle fuses with the plasma membrane and releases protein outside the cell

differences with TEM and SEM

TEM: electron beam passes through the specimen TEM: produces a 2D TEM: needs to be thinly sliced

SEM: electrons are scattered from the surface of the specimen and detected SEM: produces a 3D image SEM: doesnt need to be thinly sliced

what type of organelles in prokaryotic cells act as nutrient

lipid droplets glycogen granules

facts supporting endosymbiotic theory

Mitochondria and chloroplast have their own DNA

DNA in mitochondria and chloroplast is arranged similarity to prokaryotes

When mitochondria and chloroplas divide individually

main components of cytoskeleton

microfilaments

How would you be able to see mesosome in the cell membrane of prokaryotic cell

using an electron microscopes

what did scientists used to think to mesosomes were vs what they think it is now

suggested mesosomes played a role respiration

now think they are an artefact created when bacterial cells are prepared for electron microscopy

out of transmission electron microscopes

scanning electron microscopes and light microscopes. Which one have better resolution and magnification

What is a limitation of light microscope

-The light microscope's resolution is limited by the wavelength of light

golgi apparatus function

1. processes and packages proteins

2. makes lysosomes

what roles are microfilaments involved

involved in cell movement involved in cell division

what can proteins be used for

enzymes structural proteins transport molecules

cillia function

microtubles allow cillia to moves this movement is used by the cell to move substances along the cell surface

how many micromenters in millimeters

1 micrometer = 1000 millimeters

What are the 2 types of electron microscopes

transmission electron microscope (TEM) and scanning electron microscope (SEM)

magnification question

magnification = Image size/ actual size

nucleolus function

site of ribosome synthesis

Mitochondria function

Site of aerobic respiration and where energy is stored as ATP

function of nuclear pores

allows substances to enter and leave the nucleus

example of proteins that are secreted from cells

• hormones

• antibodies

examples of proteins that remains in the cell of the cytoplasm

same enzyme

membrane function

controls the movement into and out of cells

chloroplast function

site of photosynthesis

where are nuclear pores found

studded around a nuclear envelope

what determines the order of amino acids in a specific protein

genes

what is nucleoplasm

the fluid inside the nucleus

function of vesicle

Transport substances in and out of cell & between organelles

centriole function

involved in separation of chromosomes during cell division

what are mesosomes

infoldings in the cell membrane of prokaryotic cells

What is the endosymbiotic theory?

the mitochondria and chloroplast organelles were formly prokaryotes and that large prokaryotes would engulf the bacteria that would photosynthesise and then one that could store ATP.

what are microfilaments formed from

actin

how are microtubles formed

tublin dimers polymerise and form microtubles

roles of intermediate fibres

strengthen the cell

what do DNA and histone proteins form

chromatin

key features of eukaryotic cell

DNA in a membrane bound nucleus DNA is tightly wrapped around histones DNA is a linear molecule meaning end of DNA molecule in a chromosome aren't joined together to join a loop

what type of ribosomes do prokaryotic cells have

70S

What type of ribosomes do eukaryotes have?

80s

what is the use of pili in a prokaryotic cell

they help bacteria attach to other substances or other bacteria's

how is bacterial cells having plasmids important

plasmids provides bacteria with genetic advantages

types of prokaryotes

Bacteria and Archaea

Types of eukaryotic cells

animal cells

which ribosomes are bigger

the eukaryotic or prokaryotic

what is the cell wall of bacteria made from

peptidoglycan

what can happen when 2 bacteria are attached to one another because of the pili

DNA can be transferred from one to another

roles of microtuble

• involve in movement of organelles

• determines shape of cell

• form spindle fibre

what is the cytoskeleton

a complex network of protein fibres running through the cytoplasm

pros and cons of an electron microscope

+ve) Electron microscope have a better resolution than a light microscope -ve) As inside is a vacuum

how can an electron have a wavelength

electrons have properties of both particles and waves so can have a wave length

resolution meaning

The ability to distinguish between two separate points

example on how intermediate fibres help skin

as skin is prone to mechanical stresses due to movement and intermediate fibres prevent stresses from damaging the cells

where are ribosomes produced

in the nucleolus

advantages & disadvantages of light microscopes

+ve) relatively cheap compared to electron microscopes +ve) relatively quick preparation +ve) can view dead aswell as living material -ve) lower resolution than electron microscopes -ve) limited depth of field

what does a lysosome look like

a round organelle surrounded by a membrane with no clear internal structure

how do microtubles help to determine the shampe of cells

by forming a complex network of fibres in cytoplasm

what do lysosomes contain

digestive enzymes

key features of prokaryotic cells

• no membrane bound organelles DNA found in cytoplasm

• DNA arranged in circular chromosomes with no free ends

• DNA not bound to histone

• have plasmids

Why is their a vaccum inside of the scanning and transmission of electron microscope

Inside the SEM and TEM is a vacuum so the electrons can pass through without bouncing of molecules in the air

where is the final image of an image produced from a SEM put

final image is produced on fluorescent screen

why is important that the inside of the electron microscopes is a vacuum

the electrons won't be bouncing of molecules in the air

Why is their a vacuum inside scanning electron microscopes and transmission electron microscopes

Inside the SEM and TEM is a vacuum so the electrons can pass through without bouncing of molecules in the air