Cell Structure + Transport

Question 1

Cell requirements

Answer 1

They need to be in a stable environment that continually supplies the materials they need and continually removes any materials they produce.

Question 2

Vesicle

Answer 2

A membrane bound sac that transports materials into, out or within the cell

Question 3

Cell membrane

Answer 3

Outer boundary of the cell that separates it from neighbouring cells and from the external environment.

Question 4

Golgi body

Answer 4

Modify proteins and package them in vesicles for secretion from the cell.

Question 5

Mitochondria

Answer 5

Release energy for the cell through the process of respiration.

Question 6

Nucleus

Answer 6

Contains the genetic material of the cell, mostly DNA. Separated form cytoplasm by nuclear membrane.

Question 7

Nucleolous

Answer 7

Composed mainly of RNA.

Question 8

Lysosomes

Answer 8

Small spheres that contain enzymes able to break down proteins, lipids, nucleic acids, and some carbohydrates.

Question 9

Cytoplasm

Answer 9

Thick fluid within the cell membrane and all the structures suspended in it.

Question 10

Centrioles

Answer 10

Involved in the reproduction of the cell.

Question 11

Smooth endoplasmic reticulum

Answer 11

Has no ribosomes attached.

Question 12

Rough endoplasmic reticulum

Answer 12

Has ribosomes attached.

Question 13

Endoplasmic reticulum

Answer 13

Pairs of parallel membranes connecting the cell membrane with the nuclear membrane.

Question 14

Ribosomes

Answer 14

Most are attached to membranes. Amino acids are joined together at ribosomes to make proteins.

Question 15

Cytoskeleton

Answer 15

Gives the cell its shape and assists the movement of materials, organelles or the whole cell.

Question 16

Cell membrane structure

Answer 16

• Phospholipid bilayer: Hydrophobic tail, hydrophilic head
• Channel and carrier protein (integral proteins)
• Cell identity marker
• Cholesterol

Question 17

Functions of cell membrane

Answer 17

1. Acts as a physical barrier
2. Regulates passage of materials
3. Sensitive to changes
4. Supports the cell

Question 18

Simple diffusion

Answer 18

Is the passive movement of molecules from an area of high concentration to an area of low concentration, down their concentration gradient, without the need for energy (ATP). (Oxygen)

Question 19

Facilitated transport

Answer 19

Proteins in the cell membrane allow molecules to be transported across the membrane. Channel proteins and carrier proteins.

Question 20

Osmosis

Answer 20

The passive movement of water molecules across a differentially permeable membrane from an area of low solute concentration (high water concentration) to an area of high solute concentration (low water concentration). This process continues until equilibrium is reached. (In RBCs water moves in and out of the cell)

Question 21

Active transport

Answer 21

Form of facilitated transport. Movement of molecules across a cell membrane from an area of lower concentration to an area of higher concentration, against their concentration gradient. REQUIRES ENERGY. (Sodium and potassium)

Question 22

Vesicular transport

Answer 22

The process by which large molecules or particles are moved into or out of a cell through vesicles, small membrane-bound sacs. This type of transport is used for substances that are too large or bulky to pass through the cell membrane. Endocytosis and Exocytosis

Question 23

Endocytosis

Answer 23

The process by which a cell takes in material by engulfing it with its membrane, forming a vesicle.

Question 24

Exocytosis

Answer 24

The process by which materials are expelled from the cell through the fusion of a vesicle with the cell membrane.

Question 25

Pinocytosis

Answer 25

Form of endocytosis where liquids are taken into the cell.

Question 26

Phagocytosis

Answer 26

Form of endocytosis where solid particles are taken into the cell.

Question 27

Why are cells so small

Answer 27

Surface area to volume ratio and efficient diffusion.