ALEVEL Biology AQA- "Cells"

What type of cells are more complex organisms?

eukaryotic cells

Fill in the gap: "prokaryotic cells are often ____________ __________ ______________"

single celled organisms

Where is a cell membrane found?

found on the inside of cell walls

What is a cell membrane compromised of?

lipids and proteins

What does the cell membrane do?

regulates the movement of substances into and out of the cell

Why does the cell membrane have a receptor?

to respond to chemicals

What is the nucleus surrounded by?

a double membrane

What is the double membrane surrounding the nucleus called?

Nuclear envelope

What does the nuclear envelope have?

nuclear pores

What does the nucleus contain?

Linear DNA in the form of chromatin

What is chromatin wrapped around? What is this called?

A protein, called Histones

What is embedded in the nucleoplasm?

nucleolus

What does a nucleus do?

Controls the cells activities

What does the DNA within the nucleus do?

DNA codes for the formation of proteins via mRNA which is released through nuclear pores

Where are ribosomes made?

nucleolus

Describe the structure of a mitochondria?

oval shape with a double membrane

What does the inner membrane do in mitochondria? what is the name of what is formed?

folds to make structures called cristae

What is the fluid inside mitochondria called?

matrix

What does the matrix fluid inside the mitochondria contain?

contains enzymes, needed for aerobic respiration

What does the mitochondria contain?

its own DNA and ribosomes

What is the function of mitochondria?

The site of aerobic respiration to release energy

What is golgi?

stack of fluid filled, membrane bound sacs

What is seen at the edge of golgi?

Vesicles

What does golgi modify?

proteins

What does Golgi make?

lysosomes

Describe the structure of Vesicles

small membrane bound, fluid filled, sac

What is vesicles produced from?

Often produced from the golgi apparatus

What do vesicles do?

store and transports proteins and lipids around and out of the cell

Describe the structure of Lysosomes.

circular organelle with a single membrane

What is a lysosome?

A vesicle which contain digestive enzymes

What is the name of the digestive enzymes lysosomes contain?

lysozymes

What is lysosomes used for?

Is used to separate digestive enzymes from the other parts of the cell, used to digest foreign material and 'worn' organelles

What do centrioles do?

creates microtubes during mitosis (prophase) to attach to centromeres on sister chromotids to separate them

What are spindle fibers made of?

microtubules

Describe the size of ribosomes

small

Where are ribosomes found?

often found free in the cytoplasm or attached to endoplasmic reticulum (rough)

What are ribosomes a compromise of?

proteins and RNA

Do ribosomes have a membrane?

no membrane

what are ribosomes the site of?

protein synthesis

What is the rough endoplasmic reticulum?

conjoined fluid filled membranes which are embedded with ribosomes

What does the rough endoplasmic reticulum do?

folds and processes polypeptides into proteins which have been created by ribosomes

What is the smooth endoplasmic reticulum?

conjoined fluid filled membranes which are without ribosomes

What does the smooth endoplasmic reticulum do?

synthesis and process of lipids ad carbohydrates

What are the 3 main types of filament proteins that make up the cytoskeleton?

actin filaments
microtubes
intermediate filaments

What is the cytoskeleton needed for?

Needed to moe organelles around a cell to specific locations

What do the filaments that make up the cytoskeleton provide for the cell?

Provides support for the cell

What does the cytoskeleton allow?

Allows cells to change shape for movement

What cells are chloroplasts found in?

plant and algal cells

What surrounds chloroplasts? What is it called?

double membrane
chloroplast envelope

What is the fluid inside the chloroplast envelope called?

stroma

What does chloroplast contain? What is this called?

flattened sacs individually called thylakoids

What do thylakoids contain?

chlorophyll

What is lamellae?

the interconnections between grana

What is grana?

stack of thylakoids

What are chloroplasts the site of?

photosynthesis

What can be found in chloroplasts? Why?

starch grains, as it is the site of photosynthesis

What 2 things do chloroplasts also contain?

their own DNA
ribosomes

Why do chloroplasts contain ribosomes?

to synthesise their own proteins for photosynthesis

What is a vacuole?

single membrane bound organelle, containing cell sap

What is the name of the membrane surrounding the vacuole?

tonoplast

What does cell sap consist of?

consists of a solution of mineral salts, sugars, amino acids, wastes and some pigments

What does a vacuole contain? What is this used for?

contains the pigments which may colour petals used to attract pollinators

What is the vacuole in plants cells for?

tugor support

What does the vacuole act as?

a temporary food store

What cell types are cell walls found in?

bacteria
plants
fungi
algae

In plant and alage cells, what is the cell wall composed of?

cellulose

Describe the location of cellulose fibres.

the cellulose fibres are embedded in a matrix

What is the cell wall compromised of in fungi cells?

chitin

What is the middle lamellae?

the layer between the adjecent cell wall

What does the middle lamellae do?

cements cells together

What is the cell wall needed for?

cellular support under turgor pressure from osmosis

What is plasmodesmata?

pores in cell wall

What plasmodesmata allow?

allows the flow of water from one plant cell to the next

Algal cells have a cell wall of what?

cellulose and chloroplasts

What is special about alagal cells?

they can be unicellular or multicellular

What is the difference between plant and algal cells? (in terms of chloroplast)

alagal cells often have one large chloroplast rather than many smaller ones like plant cells

What is special about fungal cells?

they can be multicellular or unicellular

Give an example of a unicellular fungal cell.

yeast

Give an example of a multicellular fungal cell.

mushroom

True or False: Fungal cells have chloroplast

False; fungal cells do not have chloroplasts

What makes up an organism?

cell → tissue → organ → organ system → organism

Phosolipid bilayer membrane diagram

Nucleus diagram

Mitochondrian diagram

Golgi diagram

Chloroplast diagram

Vesicles diagram

Ribosomes diagram

Rough endoplasmic reticulum diagram

Smooth endoplasmic reticulum diagram

Vacuole diagram

Cell wall diagram

Compare eukaryotic cells to prokaryotic cells. (in terms of size)

prokaryotic cells are much smaller than eukaryotic cells

What type of cells are unicellular (single celled)?

prokaryotic cells

Compare the structure of eukaryotic and prokaryotic.

prokaryotic cells are much simpler in structure than eukaryotic cells

state one difference between prokaryotic and eukaryotic cells.

prokaryotic cells have no membrane bound organelle

Where is bacterial DNA found?

nucleoid

describe the DNA in a nucleoid

the DNA is free in the cell wall and not associated with proteins. It exists as a single circular chromosome.

What are plasmids?

smaller circular pieces of DNA that can replicate independently from the main chromosomal DNA

Where are the genes of antibiotic resistance often found?

Plasmids