Yr 11 - SCB - B2.4 - Introduction

Question 1

Cell (plasma) membrane function/structure

Answer 1

Function- Control the entry/exit of materials. Allows for different environments within cell than outside it. Separates areas within cell that need it.

Structure- Double layer of phospholipids are semi-permeable and only allows small molecules (eg water, CO2) to pass, rest needs help from proteins present

Question 2

Mitochondria function/structure

Answer 2

Function- reparation so breaking down glucose to get energy so the cell can store it as ATP bond

Structure - double membrane keeps internal environment seperate from cytoplasm. Folded inner membrane to allow for lots of enzymes to react

Question 3

Vacuoles function/structure

Answer 3

Function - they keep stored molecules seperate from cytoplasm so their contents don’t mix with cell processes

Structures- bags made of plasma membrane. Usually inactive and generally in middle of plant cell where diffusion alone would take too long, making them larger than animal cells

Question 4

Nucleus function/structure

Answer 4

Function - controls the cell depending on which genes are being used and how they are used

Structure - Contains chromosomes (DNA) which has info needed to make proteins. RNA copies this info as needed and taken out the pores of the nucleus membrane (double membrane) to ribosomes to be translated to proteins

Question 5

ROUGH Endoplasmic reticulum (ER) function/structure

Answer 5

Function - makes proteins, especially those being secreted out the cell

Structure - large networks of membranes covered in ribosomes. As proteins are made they are stored inside ER before being sent in little vesicles to the Golgi

Question 6

SMOOTH Endoplasmic reticulum (ER) function/structure

Answer 6

Function - Makes steroid hormones, detoxifies poisons, involved in muscle contraction, Ca storage, makes phospholipids for new membrane

Structure - A network of membranes. The proteins embedded in the membrane may be transport channels or else enzymes that enable smooth ER to catalyse reactions

Question 7

Ribosomes function/structure

Answer 7

Function - Makes proteins

Structures - If free in cytoplasm, usually to make proteins for the cell. If bound to the ER, usually to make proteins for export.

Question 8

Nucleus function/structure

Answer 8

Not important

Question 9

Golgi bodies function/structure

Answer 9

Function - process and package proteins for export out of the cell

Structure - A stack of membranous sacs. Vesicles of proteins arrive from the rough ER and fuse with one side of Golgi. Proteins move through the vesicles and are modified until a vesicle fuses with the cell and the contents are secreted.

Question 10

Lysosomes function/structure

Answer 10

Function - Digested particles of food that have been engulfed by the cell. Breaking down old worn organelles so molecules can be reused. Involved in the programmed death of the cell

Structure - Small vesicles that contain digestive enzymes. When they fuse with a food vacuole or an old organelle the enzymes break it down. The membrane keep the enzymes seperate from the rest of the cell so they don’t cause damage

Question 11

Chloroplasts function/structure

Answer 11

Function - Carry out photosynthesis

Structure - Stacks of round flat membrane sacs called grana which contain green chlorophyll pigment which absorbs light. The stroma (fluid around grana) is where the H and O (water split using light energy) are joined to C to make glucose (respiration)

Question 12

Cell wall function/structure

Answer 12

Function - provide support to plant cells. When cells are full of water they push against the wall and are rigid

Structure - Made of laters of cellulose fibres. Each layer go in a different direction. The layers are porous meaning they freely let substances in and out.

Question 13

Cilia function/structure

Answer 13

Function - Movement eg paramecium

Structure - Many short hair like structures that beat with a power stroke and then a recovery stroke

Question 14

Flagella function/structure

Answer 14

Function - Movement eg euglena

Structure- A long while like tail that whips side to side or spinning to propel a cell along

Question 15

Label plant and animal cell

Answer 15

.