biology- cell structure (1)✅

What is the function of the cell surface membrane?

Regulates the transport of substances in and out of the cell (partially permeable membrane)

What is the function of the mitochondria?

Site of aerobic respiration

What is the function of Ribosomes?

Site of protein synthesis

What is the function of Vesicles?

Transport proteins+releases them to the outside cell via exocytosis

What is the function of Golgi body?

Modifies + packages proteins into vesicles

What is the function of centriole?

Controls movement of chromosomes during cell division

what is a pair of centrioles called?

centrosome

what are centrioles made of?

microtubules

what are the 2 main functions of centrioles?

• During mitosis and meiosis, play a role in assembly of spindle fibres

• Both cilia and flagella have 9 paired of microtubules arranged in a circle running through the centre, with another pair of microtubules in the centre (9+2 structure), allows them to move

How do cilia and flagella move/ bend according to centrioles/ microtubules?

Using energy from ATP, the pairs of microtubules can move relative to the pairs next to them which creates the bending motion of these organelles

How do we know that centrioles aren’t essential for spindle assembly?

Because flowering plants form spindle fibres but do not have centrioles

What is the function of SER?

Involved in lipid synthesis

What is the function of RER?

Synthesises + transport proteins

What is the function of nuclear pore?

Allows exits ribosomes + mRNA

What is the function of nucleus ?

Contains genetic material and controls activities of the cell

What is the function of the nuclear envelope?

Pores on envelope allow exit og ribosomes and mRNA

What is the function of lysosome?

Contains digestive enzymes that break down old organelle and pathogens

What is the function of cell wall?

Made of cellulose/ chitin / peptidoglycan - gives strength and shape to cell (stops it bursring)

What's the function of chloroplast?

Site of PS

What's the function of vacuole?

Contains cell sap - helps regulate osmotic properties cell

What's the function of tonoplast?

Surrounds vacuole, regulates entry/exit of substances in/out of the vacuole

What are 5 things plant cell have that animal cells don't?

• Large permanent vacuole

• Chloroplast

• Tonoplast

• Cellulose cell wall

• Plasmodemata

What are 2 things animal cells have that plant cells don't?

• Centrioles

• Glycogen granules

What is the structure of the cell surface membrane?

A phospholipid bilayer with extrinsic and intrinsic proteins

What is the structure of the mitochondria?

Double membrane: smooth outer membrane and inner one which is highly folded to form cristae. Inside inner membrane is the matrix, aqueous solution containing mitochondrial DNA, ribosomes and enzymes involved in oxidation.

Why is the inner membrane of the mitochondria highly folded?

Increases the surface area for the reactions of cellular respiration.

What is the structure of ribosomes?

Not bounded by a membrane. Consists of a large and small sub unit made of protein and nucleic acid.

What is the structure of a vesicle?

Membrane bound sack.

What is the structure of the Goldie body?

Stack of membrane bound sacks.

What is the structure of a centriole?

9 sets of 3 parallel microtubules arranged in a hollow cylinder. (9×3 arrangement)

What is the structure of the smooth endoplasmic reticulum?

A complex network of flattened, interconnecting, membrane bound sack called cisternae. (Smooth appearance)

What is the structure of the rough endoplasmic reticulum?

A complex network of flattened, interconnecting, membrane bounds called cisternae (grainy appearance)

What is the structure of a nuclear pore?

Gap in nuclear envelope.

What is the structure of the nucleus?

Has a double membrane perforated by pores

What is the structure of the nucleolus?

A dense region of the nuclear plasm comprising heterochromatin. (Membrane-less)

What is the structure of the nuclear envelope?

A double membrane with pores

What is the structure of a lysosome?

Membrane bound sack containing digestive enzymes

What is the structure of the cell wall?

Consists of cellular microfibrils and other polysaccharides

What is the structure of a chloroplast?

Double membrane- has a system of membranes running through it stacked to form a grana. Stroma contains ribosomes and starch grains

What’s the structure of a large permanent vacuole?

Sack bound by a single membrane and contains cell sap

what is the structure of a tonoplast?

partially permeable membrane surrounding the vacuole

what is the structure of the cytoskeleton?

Microfilaments – Actin, a concatile fibre

Intermediate fibres – strengthens cell

Microtubules- tubulin forms scaffold like structure

What the definition of cytoskeleton?

Complex network of protein fibres running throughout cytoplasm

What are microfilaments?

Narrow fibres containing the protein actin, involved in cell movement

Why is the protein actin useful in microfilaments?

Actin fibres can contract- cell movement

what are intermediate fibres?

Formed from a number of different proteins and the role is to strengthen the cell

Whats the role of microtobules?

• involved in movement of organelles

• Form the spindle fibres which are involved in movement of chromosomes during mitosis and meiosis

• Helps to determine the shape of the cell

What's the role of the Cytoskeleton?

• Maintain shape

• Movement of cilia/flagella

• Changing shape of cell

• Makes/hold organelles in place

• Movement of chromosomes

what’s 2 differences between DNA and RNA?

• RNA has ribose not deoxyribose

• RNA has the base urasil not thymine

Outline how cell organelles work together to produce and secret proteins?

• A gene is transcribed to mRNA in the nucleus

• mRNA then leaves the nucleus via the nuclear pore

• The mRNA travels to and associates with a ribosome (on the RER)

• The ribosome is the site of protein synthesis

• The protein is transported in a transport vesicle to the Golgi body

• The Golgi body processes and modifies the protein

• The Golgi body then packages the protein into a secretory vesicle

• The secretory vesicle travels to and fuses with the cell surface membrane

• The contents of the secretory vesicle are released from the cell

• Via exocytosis

What is the function of the slime capsule?

• Protection from recognition of immune system

• Protection from dehydration

What is the function of cilia?

Create a current

What is the function of mesosome?

Photosynthesis or respiration

What is the function of plasmids?

For antibiotic resistance

What is the function of 70s ribosomes?

Site of protein synthesis

What is the function of cytoplasm?

Site of metabolic reactions

What is the function of a loop of DNA?

Codes for proteins and the control of cell activities

What is the function of flagellum?

Movement

What is the structure of a slime capsule?

Layer of polysaccharide and polypeptide

What is the structure of cilia?

Short hair like structure

What is the structure of mesosome?

Infolding of cell membrane

What is the structure of plasmids?

Short loop of DNA with few genes

What is the structure of 70s ribosomes?

Smaller than eukaryote

What is the structure of a loop of DNA?

loop of DNA without histones

What is the structure of the flagellum?

Long whiplike structure