Biology - Review Qns - 2.1 & 2.2 Flashcards Preview

LPC 2018 Biology > Biology - Review Qns - 2.1 & 2.2 > Flashcards

Flashcards in Biology - Review Qns - 2.1 & 2.2 Deck (18):
1

Core Term

The cell theory

3 Points

- All organisms are composed of cells (or the products of cells)
- All cells come from pre-existing cells
- The cell is the smallest living organisational unit.

2

Definition

Eukaryotes

Include protists, fungi, plants & animals.

Eukaryotic cells contain membrane-bound organelles in the cell cytoplasm.

3

Common features shared by all cells

4 items

Plasma membrane
Cytoplasm
Genetic material in the form of DNA
Ribosomes.

4

Prokaryotic cells

4 characteristics

Simple structure
A nucleoid lacking a membrane
Scattered ribosomes
DNA mainly in a single-stranded loop in the nucleoid.

5

Eukaryotic

4 Characteristics

Complex structure
Membrane-bound nucleus
Many organelles in the cell cytoplasm
DNA mainly in chromosomes in the nucleus.

6

Plant cells

8 main structures

Nucleus
Vacuole
Golgi apparatus
Rough and smooth endoplasmic reticulum
Ribosomes
Plastids
Mitochondria
Cell wall

7

Animal Cells

9 main structures

Nucleus
Ribosomes
Golgi apparatus
Rough and smooth endoplasmic reticulum
Vacuoles
Mitochondria
Lysosomes
Vesicles
Centrioles

8

Organic versus Inorganic substances

Contrast these types

Organic substances:
  - Contain carbon & hydrogen
  - Are found in living things
Inorganic compounds
  - Those that are not organic
  - e.g. oxygen, water & carbon dioxide

9

Main types of Organic Compounds

List of 4

Carbohydrates
Proteins
Nucleic acids
Lipids

10

Describe

Biomacromolecules

Large organic molecules
Formed by joining together many smaller units (monomers)
Monomers form a chain or polymer.
Examples: polysaccharides, nucleic acids and proteins

11

Core Term

Carbohydrates

5 points

- are an important source of chemical energy for
living organisms (e.g. glucose)
- are used as energy reserves in plants (e.g. starch) and animals (e.g. glycogen)
- form structural components such as cell walls (e.g. cellulose in plants).
- form part of both DNA and RNA
- combine with proteins and lipids to form glycoproteins and glycolipids, as in cell membranes.

12

Core Term

Lipids

Fatty substances that are not soluble in water
Roles:
  -  the main component of cell membranes
  - store energy
  - play an important role as hormones

13

Core Term

Nucleic acids

Contain the genetic material of all organisms.
There are two types:
- DNA-carries the 'instructions' required to assemble proteins
- RNA-plays a major role in the manufacture of proteins.
 

14

Functions of Proteins

List of 5

Catalyse cellular reactions
Play an important role as hormones
Act as carrier molecules
Form structural components in organisms
Play an important role in the immune system (e.g. antibodies and antigens)

15

Important properties of water

Cohesiveness
Surface tension
Heat capacity
 pH

16

Main source of Carbon?

Atmospheric carbon dioxide

17

Nitrogen

Component of all proteins

"fixed' from the atmosphere by certain bacteria
 

18

Minerals

Form important parts of organic molecules such as enzymes and structural molecules