Cells

Question 1

Features of Animal Cells

Answer 1

Cell membrane
Nucleus
Ribosomes
Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Golgi apparatus
Mitochondria
Lysosomes
microtubules

Question 2

Features of Plant cell

Answer 2

Same as animal cell and…
Chloroplast
Large vacuole
Cell wall
Plasmodesmata

Question 3

Cell Surface membrane

Answer 3

Selectively permeable membrane in plant and animal cells that allows for the exchange of certain biological molecules and ions.
Extremely thin with trilaminar appearance
It is comprised of phospholipid bilayers which are assembled with the hydrophilic phosphate heads facing the aqueous environment (inside and outside the cell) and the hydrophobic tails facing each other.

Question 4

Organelles

Answer 4

Functionally and structurally distinct part of a cell, usually membrane bound.
Main features of typical animal and plant cells viewed under a school/simple light microscope:

Question 5

Function of Cell Surface Membrane

Answer 5

Barrier between cytoplasm and external environment
Cell signalling
Cell recognition (surface antigens)
Cell-to-cell adhesion
Site for enzyme catalysed reactions
Anchoring the cytoskeleton
Selection of substances that enter/leave the cell
Formation of Hydrogen bonds with water for stability

Question 6

Nucleus

Answer 6

Largest organelle
Surrounded by a double membraned nuclear envelope Continuous with (RER).
Nuclear pore
Substances leaving: mRNA and ribosomes for protein synthesis.
Substances entering: protein, nucleotide, ATP, & some hormones.
Chromosome
Nucleolus (0.2-0.5μm) one or more found (nucleoli) containing DNA and RNA.

Question 7

Ribosome

Answer 7

the site at which mRNA is translated into polypeptides with the help of tRNA, therefore help with protein synthesis.
They are not membrane bound and made up of rRNA and rProteins.
80S ribosomes: in the cytoplasm and R.E.R
70S ribosomes: in chloroplast and mitochondria.
Small subunit: site of translation (mRNA binds here and is read by this unit)
Large subunit: joins amino acids to form polypeptide.

Question 8

Endoplasmic Reticulum (smooth)

Answer 8

-For lipid synthesis and steroids
-Meshwork of tubular membrane vesicles
-With fluid filled sacs that have no ribosome on its surface

Question 9

Endoplasmic Reticulum (rough)

Answer 9

-Extensive membrane system -80S ribosomes which produce the rough appearance.
-Provides a pathway for transport of materials through cells
Forms a complex 3D system of sheet like membranes and tubes enclosing fluid-filled sacs.
Proteins made by ribosomes on RER enter sacs and move through them.
Transport vesicles bud off from the RER and join forming the Golgi body.